What is the probability that in group of 10 random people, at least two of them have the same letter in initials (such as LMS for Laurel Marie Sander), assuming that each triple of initials is equally likely.

Answers

Answer 1

Answer:

So the probability is P=0.00256.

Step-by-step explanation:

We have 26 letters, so the probability that the first letter in the name is the same is 1/26.

The probability that the second letter in the name is the same is 1/26 and the probability that the third letter in the name is the same is 1/26.

Out of ten people we choose 2.

So the probability is:

[tex]P=C_2^{10}\left(\frac{1}{26}\right)^3\\\\P=\frac{10!}{2!(10-2)!}\cdot \left(\frac{1}{26}\right)^3\\\\P=\frac{45}{17576}\\\\P=0.00256\\[/tex]

So the probability is P=0.00256.


Related Questions

Find a formula for the general term of the sequence 5 3 , − 6 9 , 7 27 , − 8 81 , 9 243 , assuming that the pattern of the first few terms continues. SOLUTION We are given that a1 = 5 3 a2 = − 6 9 a3 = 7 27 a4 = − 8 81 a5 = 9 243 .

Answers

Answer:

The formula to the sequence

5/3, -6/9, 7/27, -8/81, 9/243, ...

is

(-1)^n. (4 + n). 3^(-n)

For n = 1, 2, 3, ...

Step-by-step explanation:

The sequence is

5/3, - 6/9, 7/27, - 8/81, 9/243, ...

We notice the following

- That the numbers are alternating between - and +

- That the numerator of a number is one greater than the numerator of the preceding number. The first number being 5.

- That the denominator of a number is 3 raised to the power of (2 minus the position of the number)

Using these observations, we can write a formula for the sequence.

(-1)^n for n = 1, 2, 3, ... takes care of the alternation between + and -

(4 + n) for n = 1, 2, 3, ... takes care of the numerators 5, 6, 7, 8, ...

3^(-n) for n = 1, 2, 3, ... takes care of the denominators 3, 9, 27, 81, 243, ...

Combining these, we have the formula to be

(-1)^n. (4 + n). 3^(-n)

For n = 1, 2, 3, ...

The final formula is [tex]a_n = ((-1)^{ (n+1)} * (n + 4)) / (3^n).[/tex]

Finding the General Term of the Sequence

The sequence given is: 5/3, -6/9, 7/27, -8/81, 9/243. To find the formula for the general term (nth term) of this sequence, we need to carefully analyze the patterns in both the numerators and the denominators separately.

Numerator Analysis: The numerators of the given sequence are 5, -6, 7, -8, 9. Notice the pattern: the numerators alternate between positive and negative signs and increase by 1 each time. Thus, for the nth term, the numerator can be given by the formula:[tex](-1)^{(n+1)} * (n + 4).[/tex]Denominator Analysis: The denominators of the sequence are 3, 9, 27, 81, 243. These form a geometric sequence where each term is multiplied by 3. The nth term of this sequence can be expressed as [tex]3^n.[/tex]

Combining the results from the numerator and denominator analysis, the general term of the sequence, an, is:

[tex]a_n = ((-1)^{ (n+1)} * (n + 4)) / (3^n).[/tex]

Complete Question:- Find a formula for the general term of the sequence 5 3 , − 6 9 , 7 27 , − 8 81 , 9 243 , assuming that the pattern of the first few terms continues

After removing all of the clubs from a deck of cards, you are left with a 39 card deck with Hearts, Diamonds, and Spades. Answer the following questions assuming that after each draw of a card, that card is returned to this deck and reshuffled.

What is the probability of :A) drawing a red card ?B) drawing a heart or a red card?C) drawing a jack or a red card?

Answers

Answer:

(a)2/3

(b)2/3

(c)9/13

Step-by-step explanation:

Total Number of Cards in new Deck=39

Hearts(Red)=13

Diamonds(Red)=13

Spades(Black)=13

(a)P(drawing a red card)

Total number of red cards = 13+13=26

P(drawing a red card)=26/39=2/3

(b)Drawing a heart or a red card

Number of Hearts=13

Number of red cards=26

Number of Red Hearts = 13

Since the two events are not mutually exclusive

P(Hearts or Red) = P(Hearts) + P(Red) - P( Hearts and Red)

P(H∪R)=P(H)+P(R)-P(H∩R)

=13/39 + 26/39 - 13/39

=26/39 =2/3

(c)Drawing a jack or a red card.

Number of Jacks=3

Number of red cards=26

Number of Red Jacks = 2

Since the two events are not mutually exclusive

P(Jack or Red) = P(Jacks) + P(Red) - P( Jacks and Red)

P(J∪R)=P(J)+P(R)-P(J∩R)

=3/39 + 26/39 - 2/39

=27/39 =9/13

Please help!!!!!! I’ll mark you as brainliest if correct

Answers

Answer: 771,243

Step-by-step explanation:

The probability that an Oxnard University student is carrying a backpack is .70. If 10 students are observed at random, what is the probability that fewer than 7 will be carrying backpacks

Answers

Answer:

35.03% probability that fewer than 7 will be carrying backpacks

Step-by-step explanation:

For each student, there are only two possible outcomes. Either they are carrying a backpack, or they are not. The probability of a student carrying a backpack is independent from other students. So we use the binomial probability distribution to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

In which [tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

And p is the probability of X happening.

The probability that an Oxnard University student is carrying a backpack is .70.

This means that [tex]p = 0.7[/tex]

If 10 students are observed at random, what is the probability that fewer than 7 will be carrying backpacks

This is [tex]P(X < 7)[/tex] when [tex]n = 10[/tex]. So

[tex]P(X < 7) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6)[/tex]

[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]

[tex]P(X = 0) = C_{10,0}.(0.7)^{0}.(0.3)^{10} = 0.000006[/tex]

[tex]P(X = 1) = C_{10,1}.(0.7)^{1}.(0.3)^{9} = 0.0001[/tex]

[tex]P(X = 2) = C_{10,2}.(0.7)^{2}.(0.3)^{8} = 0.0014[/tex]

[tex]P(X = 3) = C_{10,3}.(0.7)^{3}.(0.3)^{7} = 0.0090[/tex]

[tex]P(X = 4) = C_{10,4}.(0.7)^{4}.(0.3)^{6} = 0.0368[/tex]

[tex]P(X = 5) = C_{10,5}.(0.7)^{5}.(0.3)^{5} = 0.1029[/tex]

[tex]P(X = 6) = C_{10,6}.(0.7)^{6}.(0.3)^{4} = 0.2001[/tex]

[tex]P(X < 7) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3) + P(X = 4) + P(X = 5) + P(X = 6) = 0.000006 + 0.0001 + 0.0014 + 0.0090 + 0.0368 + 0.1029 + 0.2001 = 0.3503[/tex]

35.03% probability that fewer than 7 will be carrying backpacks

Final answer:

To find the probability that fewer than 7 students will be carrying backpacks, use the binomial probability formula. The final probability is 0.9143, or 91.43%.

Explanation:

To find the probability that fewer than 7 students will be carrying backpacks, we can use the binomial probability formula. In this case, the probability of success (carrying a backpack) is 0.70. The number of trials is 10. We want to find the probability of getting fewer than 7 successes.

We can calculate this by finding the sum of the probabilities of getting 0, 1, 2, 3, 4, 5, and 6 successes, using the binomial probability formula for each value. Then, we subtract this sum from 1 to get the probability of getting fewer than 7 successes.

The final probability for this scenario is 0.9143, or 91.43%.

An eight-sided die, which may or may not be a fair die, has four colors on it; you have been tossing the die for an hour and have recorded the color rolled for each toss. What is the probability you will roll a brown on your next toss of the die? Express your answer as a simplified fraction or a decimal rounded to four decimal places. brown purple green yellow 35 50 44 23

Answers

Answer:

The probability of rolling a brown on the next toss is 0.2303.

Step-by-step explanation:

The data recorded is:

Brown = 35

Purple = 50

Green = 44

Yellow = 23

TOTAL = 152 tosses

The probability of an event E is computed by dividing the favorable number of outcomes by the total number of outcomes.

[tex]P(E)=\frac{Favorable\ outcomes}{Total\ no.\ of\ outcomes}[/tex]

Using this formula compute the probability of rolling a brown on the next toss as follows:

[tex]P(Brown)=\frac{35}{152}= 0.2303[/tex]

Thus, the probability of rolling a brown on the next toss is 0.2303.

The data below are the ages and systolic blood pressures (measured in millimeters of mercury) of 9 randomly selected adults. What is the best predicted value for y given x = 41? Assume that the variables x and y have a significant correlation.

Answers

Answer:

[tex]\sum_{i=1}^n x_i =459[/tex]

[tex]\sum_{i=1}^n y_i =1227[/tex]

[tex]\sum_{i=1}^n x^2_i =24059[/tex]

[tex]\sum_{i=1}^n y^2_i =168843[/tex]

[tex]\sum_{i=1}^n x_i y_i =63544[/tex]

With these we can find the sums:

[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=24059-\frac{459^2}{9}=650[/tex]

[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}=63544-\frac{459*1227}{9}=967[/tex]

And the slope would be:

[tex]m=\frac{967}{650}=1.488[/tex]

Nowe we can find the means for x and y like this:

[tex]\bar x= \frac{\sum x_i}{n}=\frac{459}{9}=51[/tex]

[tex]\bar y= \frac{\sum y_i}{n}=\frac{1227}{9}=136.33[/tex]

And we can find the intercept using this:

[tex]b=\bar y -m \bar x=136.33-(1.488*51)=60.442[/tex]

So the line would be given by:

[tex]y=1.488 x +60.442[/tex]

And then the best predicted value of y for x = 41 is:

[tex]y=1.488*41 +60.442 =121.45[/tex]

Step-by-step explanation:

For this case we assume the following dataset given:

x: 38,41,45,48,51,53,57,61,65

y: 116,120,123,131,142,145,148,150,152

For this case we need to calculate the slope with the following formula:

[tex]m=\frac{S_{xy}}{S_{xx}}[/tex]

Where:

[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}[/tex]

[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}[/tex]

So we can find the sums like this:

[tex]\sum_{i=1}^n x_i =459[/tex]

[tex]\sum_{i=1}^n y_i =1227[/tex]

[tex]\sum_{i=1}^n x^2_i =24059[/tex]

[tex]\sum_{i=1}^n y^2_i =168843[/tex]

[tex]\sum_{i=1}^n x_i y_i =63544[/tex]

With these we can find the sums:

[tex]S_{xx}=\sum_{i=1}^n x^2_i -\frac{(\sum_{i=1}^n x_i)^2}{n}=24059-\frac{459^2}{9}=650[/tex]

[tex]S_{xy}=\sum_{i=1}^n x_i y_i -\frac{(\sum_{i=1}^n x_i)(\sum_{i=1}^n y_i)}{n}=63544-\frac{459*1227}{9}=967[/tex]

And the slope would be:

[tex]m=\frac{967}{650}=1.488[/tex]

Nowe we can find the means for x and y like this:

[tex]\bar x= \frac{\sum x_i}{n}=\frac{459}{9}=51[/tex]

[tex]\bar y= \frac{\sum y_i}{n}=\frac{1227}{9}=136.33[/tex]

And we can find the intercept using this:

[tex]b=\bar y -m \bar x=136.33-(1.488*51)=60.442[/tex]

So the line would be given by:

[tex]y=1.488 x +60.442[/tex]

And then the best predicted value of y for x = 41 is:

[tex]y=1.488*41 +60.442 =121.45[/tex]

Using linear regression and the provided dataset, we can predict that an individual's systolic blood pressure (SBP) at the age of 41 is approximately 142.91 millimeters of mercury, rounded to two decimal places.

here are the steps to predict systolic blood pressure (SBP) at age 41 using linear regression with the provided dataset:

Calculate the Means:

Calculate the mean (average) of ages (x) and SBP (y) from the dataset.

Mean(x) = (43 + 53 + 42 + 48 + 52 + 39 + 40 + 47 + 51) / 9 ≈ 46.33 (rounded to two decimal places)

Mean(y) = (139 + 146 + 139 + 153 + 159 + 138 + 135 + 144 + 154) / 9 ≈ 146 (rounded to the nearest whole number)

Calculate the Slope (b):

Use the formula for the slope (b) of the regression line:

b = Σ[(x - Mean(x))(y - Mean(y))] / Σ[(x - Mean(x))^2]

Calculate b using the values from the dataset and the means calculated earlier.

Calculate the Intercept (a):

Use the formula for the intercept (a) of the regression line:

a = Mean(y) - b * Mean(x)

Calculate a using the previously calculated means and the value of b.

Formulate the Regression Equation:

The regression equation is now established as:

y = a + b * x

Substituting the values of a and b, we have:

y = 118.31 + 0.6 * x

Predict SBP at Age 41:

Substitute x = 41 into the regression equation:

y = 118.31 + 0.6 * 41

Calculate y:

y ≈ 118.31 + 24.6 ≈ 142.91

So, based on these steps, the best-predicted SBP for an individual aged 41 is approximately 142.91 millimeters of mercury, rounded to two decimal places.

For more questions on regression

https://brainly.com/question/25987747

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complete question should be:

Using linear regression and the provided dataset, how can we predict the systolic blood pressure (y) for an individual with an age (x) of 41, assuming a significant correlation between age and systolic blood pressure? The dataset includes the following information:

Ages (x): 43, 53, 42, 48, 52, 39, 40, 47, 51.

Systolic Blood Pressures (y): 139, 146, 139, 153, 159, 138, 135, 144, 154.

After calculating, the best-predicted systolic blood pressure for an age of 41 is approximately 154.08 millimeters of mercury, rounded to two decimal places.

(Urgent!!) A spherical balloon is leaking air at 2 cubic inches per hour. How fast is the balloon’s radius changing when the radius is 3 inches?

Answers

initial volume of balloon =

[tex] \frac{4}{3} \times \frac{22}{7} \times r^{3} \\ \frac{4}{3} \times \frac{22}{7} \times {3}^{3} \\ 113.14[/tex]

so intial volume is 113.14 cubic inches

volume after one hour will be 113.14 - 2 = 111.14 inches

new radius

[tex]111.14 = \frac{4}{3} \times \frac{22}{7} \times {x}^{3} \\ \frac{2333.94}{88} = {x}^{3} \\ 26.52 = {x}^{3} \\ x = 2.98[/tex]

Rate change of radius is

[tex] \frac{2.98}{3} \times 100 \\ \frac{298}{3} \\ 99.93\%[/tex]

Rate change is 0.7% per hour the radius is decreasing

Frost damage to apple blossoms can severely reduce apple yield in commercial orchards. It has been determined that the probability of a late spring frost causing blossom damage to Empire apple trees in the Hudson Valley of New York State is 0.6. In a season when two frosts occur, what is the probability of an apple tree being injured in this period

Answers

Answer:

0.84 or 84%

Step-by-step explanation:

The probability of an apple tree being injured in this period, is the probability of it being injured by the first frost (0.6), added to the probability of it being injured by the second frost (0.6) minus the probability of it being injured by both frosts (0.6 x 0.6):

[tex]P = P(F_1)+P(F_2)-P(F_1\ and\ F_2)\\P=0.6+0.6-(0.6*0.6)\\P=0.84 = 84\%[/tex]

There is a 0.84 or 84% probability of an apple tree being injured in this period.

The value of probability can only be from 0 to 1. The probability of an apple tree being injured in this period is 0.84 or 84 %.

What is probability?

Probability means possibility. It deals with the occurrence of a random event. Its basic meaning is something is likely to happen. It is the ratio of the favorable event to the total number of events.

Frost damage to apple blossoms can severely reduce apple yield in commercial orchards.

It has been determined that the probability of a late spring frost causing blossom damage to Empire apple trees in the Hudson Valley of New York State is 0.6.

The probability of it being injured by first frost (0.6), added to the probability of it being injured second frost (0.6) minus the probability of it being injured by both touches of frost (0.6 × 0.6). That can be written as mathematically,

P = P(F₁) + P(F₂) - P(F₁ and F₂)

P = 0.6 + 0.6 - (0.6 × 0.6)

P 0.84

P = 84%

Thus, the probability of an apple tree being injured in this period is 0.84 or 84 %.

More about the probability link is given below.

https://brainly.com/question/795909

There are two machines available for cutting corks intended for use in bottles. The first produces corks with diameters that are normally distributed with mean 3 cm and standard deviation 0.1 cm. The second machine produces corks with diameters that have a normal distribution with mean 3.04 cm and standard deviation 0.02 cm. Acceptable corks have diameters between 2.9 cm and 3.1 cm. Which machine is more likely to produce an acceptable cork? What should the acceptable range for cork diameters be (from 3 − d cm to 3 + d cm) to be 90% certain for the first machine to produce an acceptable cork?

Answers

Answer:

a) The second machine is more likely to produce an acceptable cork.

b) Acceptable range for cork diameters produced by the first machine with a 90% confidence = (2.8355, 3.1645)

Step-by-step explanation:

This is a normal distribution problem

For the first machine,

Mean = μ = 3 cm

Standard deviation = σ = 0.1 cm

And we want to find which percentage of the population falls between 2.9 cm and 3.1 cm.

P(2.9 ≤ x ≤ 3.1) = P(x ≤ 3.1) - P(x ≤ 2.9)

We first standardize this measurements.

The standardized score for any value is the value minus the mean then divided by the standard deviation.

For 2.9 cm

z = (x - μ)/σ = (2.9 - 3.0)/0.1 = - 1.00

For 3.1 cm

z = (x - μ)/σ = (3.1 - 3.0)/0.1 = 1.00

P(x ≤ 3.1) = P(z ≤ 1.00) = 0.841

P(x ≤ 2.9) = P(z ≤ -1.00) = 0.159

P(2.9 ≤ x ≤ 3.1) = P(-1.00 ≤ z ≤ 1.00) = P(z ≤ 1.00) - P(z ≤ -1.00) = 0.841 - 0.159 = 0.682 = 68.2%

This means that 68.2% of the diameter of corks produced by the first machine lies between 2.9 cm and 3.1 cm.

For the second machine,

Mean = μ = 3.04 cm

Standard deviation = σ = 0.02 cm

And we want to find which percentage of the population falls between 2.9 cm and 3.1 cm.

P(2.9 ≤ x ≤ 3.1) = P(x ≤ 3.1) - P(x ≤ 2.9)

We standardize this measurements.

The standardized score for any value is the value minus the mean then divided by the standard deviation.

For 2.9 cm

z = (x - μ)/σ = (2.9 - 3.04)/0.02 = - 7.00

For 3.1 cm

z = (x - μ)/σ = (3.1 - 3.0)/0.02 = 3.00

P(x ≤ 3.1) = P(z ≤ 3.00) = 0.999

P(x ≤ 2.9) = P(z ≤ -7.00) = 0.0

P(2.9 ≤ x ≤ 3.1) = P(-7.00 ≤ z ≤ 3.00) = P(z ≤ 3.00) - P(z ≤ -7.00) = 0.999 - 0.0 = 0.999 = 99.9%

This means that 99.9% of the diameter of corks produced by the second machine lies between 2.9 cm and 3.1 cm.

Hence, we can conclude that the second machine is more likely to produce an acceptable cork.

b) Margin of error = (z-multiplier) × (standard deviation of the population)

For 90% confidence interval, z-multiplier = 1.645 (from literature and the z-tables)

Standard deviation for first machine = 0.1

Margin of error, d = 1.645 × 0.1 = 0.1645.

The acceptable range = (mean ± margin of error)

Mean = 3

Margin of error = 0.1645

Lower limit of the acceptable range = 3 - d = 3 - 0.1645 = 2.8355

Upper limit of the acceptable range = 3 + d = 3 + 0.1645 = 3.1645

Acceptable range = (2.8355, 3.1645)

Final answer:

To determine which machine is more likely to produce acceptable corks, we examine their distribution characteristics. Machine 2 may be more reliable due to its tighter control despite a slightly higher mean. To find a 90% certain acceptable range for Machine 1, we calculate using its standard deviation and the z-score for the 90th percentile.

Explanation:

The question involves comparing two machines based on their ability to produce corks within a specified acceptable diameter range using normal distribution properties, and calculating the range for diameters to ensure a 90% certainty of producing acceptable corks for the first machine.

Comparing the Two Machines

For the first machine with a mean diameter of 3 cm and a standard deviation of 0.1 cm, and the second machine with a mean diameter of 3.04 cm and a standard deviation of 0.02 cm, the question is which machine is more likely to produce corks within the acceptable range of 2.9 cm to 3.1 cm.

Machine 1 produces corks closer to the center of the acceptable range but with a wider spread (higher standard deviation), while Machine 2 produces corks that are skewed slightly larger but with a much tighter spread around their mean (lower standard deviation). To determine which machine is more likely to produce acceptable corks, we would need to calculate the z-scores for the acceptance limits for both machines and compare the probabilities. However, intuitively, Machine 2 might be seen as more reliable due to its tighter control (lower standard deviation), assuming its mean is not too far out of the acceptable range.

Finding the Acceptable Range for 90% Certainty

To ensure 90% certainty that a cork produced by Machine 1 falls within an acceptable diameter range, we need to determine d in the range of 3 − d cm to 3 + d cm. This involves finding the z-score that corresponds to the 5th and 95th percentiles due to the symmetric nature of normal distribution, then solving for d using the properties of normal distribution and the given standard deviation of 0.1 cm.

The z-score corresponding to the 5th and 95th percentiles (for a 90% certainty) typically falls around ±1.645. Using the formula for z-score, which is (X − μ) / σ, and solving for d, we can find the acceptable range of diameters for the first machine to produce an acceptable cork with 90% certainty.

The brain volumes ​(cm cubed​) of 50 brains vary from a low of 902 cm cubed to a high of 1494 cm cubed. Use the range rule of thumb to estimate the standard deviation s and compare the result to the exact standard deviation of 183.2 cm cubed​, assuming the estimate is accurate if it is within 15 cm cubed.

Answers

Answer:

A) Estimated standard deviation = 148cm³

B) The estimated standard deviation of 148 cm³ is less than the true standard deviation of 183.2 cm³. This estimated standard deviation is not even within 15 cm³ of the true standard deviation and thus we can say it's not accurate.

Step-by-step explanation:

From the question, the given standard deviation is 183.2 cm³

Also that the range of values is between 902 cm³ to 1494 cm³.

Range is the difference between highest and lowest values in the data set.

Thus, Range = 1494 cm³ - 902 cm³ = 592 cm³

Now, The range rule tells us that the standard deviation of a sample is approximately equal to one-fourth of the range of the data. In other words s = (Maximum – Minimum)/4

Thus, estimated standard deviation = 592/4 = 148 cm³

Tri-Cities Bank has a single drive-in teller window. On Friday mornings, customers arrive at the drive-in window randomly, following a Poisson distribution at an average rate of 30 per hour.a. How many customers arrive per minute, on average?b. How many customers would you expect to arrive in a 10-minute interval?c. Use equation 13.1 to determine the probability of exactly 0, 1, 2, and 3 arrivals in a 10-minute interval. (You can verify your answers using the POISSON( ) function in Excel.)d. What is the probability of more than three arrivals occurring in a 10-minute interval?

Answers

Answer:

a) 0.5 per minutes

b) 5 arrivals expected in 10 minutes

c) P ( x = 0 ) = 0.00673 , P ( x = 1 ) =  0.03368 , P ( x = 2 ) = 0.08422 ,P ( x = 3 ) = 0.14037                  

d)  P ( X >= 4 ) = 0.735                

Step-by-step explanation:

Given:

- The number of customer arriving at window is modeled by Poisson distribution. The distribution is given by:

                         P(x) = ( λ^x ) (e^-λ) / x!            x = 0 , 1 , 2 , 3 , ......

- Average rate λ = 30 / hr

Find:

a. How many customers arrive per minute, on average?

b. How many customers would you expect to arrive in a 10-minute interval?c. Use equation 13.1 to determine the probability of exactly 0, 1, 2, and 3 arrivals in a 10-minute interval.

d. What is the probability of more than three arrivals occurring in a 10-minute interval?

Solution:

- The average rate λ in number of customers that arrive in a minute is given by:

                              λ1 = 30 / 60 = 0.5 arrival per minutes

- The average number of customer that are expected to arrive in 10-minutes window is:

                              λ2 = 10*λ1 = 10*0.5 = 5 arrivals expected in 10 minutes

- The probability of exactly 0,1 , 2 , and 3 arrivals in 10 minute windows:

                   P ( x = 0 ) = ( 5^0 ) (e^-5) / 0! = 0.00673  

                   P ( x = 1 ) = ( 5^1 ) (e^-5) / 1! = 0.03368

                   P ( x = 2 ) = ( 5^2 ) (e^-5) / 2! = 0.08422

                   P ( x = 3 ) = ( 5^3 ) (e^-5) / 3! = 0.14037

- The probability of more than three arrivals occuring in 10-minute interval is:

                  P ( X >= 4 ) = 1 - P ( X =< 3 )

                  P ( X >= 4 ) = 1 - [ P ( x = 0 ) + P ( x = 1 ) +  P ( x = 2 ) + P ( x = 3 ) ]

                  P ( X >= 4 ) = 1 - [ 0.00673 + 0.03368 + 0.08422 + 0.14037 ]

                  P ( X >= 4 ) = 1 - [ 0.265 ]

                  P ( X >= 4 ) = 0.735

Using the Poisson distribution, it is found that:

a) 0.5 customers per minute.

b) 5 customers are expected to arrive.

c)

0.0068 = 0.68% probability of exactly 0 arrivals in a 10-minute interval.

0.0337 = 3.37% probability of exactly 1 arrivals in a 10-minute interval.

0.0842 = 8.42% probability of exactly 2 arrivals in a 10-minute interval.

0.1404 = 14.04% probability of exactly 3 arrivals in a 10-minute interval.

d) 0.7349 = 73.49% probability of more than three arrivals occurring in a 10-minute interval.

In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by:

[tex]P(X = x) = \frac{e^{-\mu}\mu^{x}}{(x)!}[/tex]

The parameters are:

x is the number of successes e = 2.71828 is the Euler number [tex]\mu[/tex] is the mean in the given interval.

Item a:

30 in one-hour(60 minutes), hence 0.5 customers per minute.

Item b:

0.5 customers per minute, hence, in a 10 minute interval, 5 customers are expected to arrive.

Item c:

[tex]P(X = x) = \frac{e^{-\mu}\mu^{x}}{(x)!}[/tex]

[tex]P(X = 0) = \frac{e^{-5}(5)^{0}}{(0)!} = 0.0068[/tex]

[tex]P(X = 1) = \frac{e^{-5}(5)^{1}}{(1)!} = 0.0337[/tex]

[tex]P(X = 2) = \frac{e^{-5}(5)^{2}}{(2)!} = 0.0842[/tex]

[tex]P(X = 3) = \frac{e^{-5}(5)^{3}}{(3)!} = 0.1404[/tex]

0.0068 = 0.68% probability of exactly 0 arrivals in a 10-minute interval.

0.0337 = 3.37% probability of exactly 1 arrivals in a 10-minute interval.

0.0842 = 8.42% probability of exactly 2 arrivals in a 10-minute interval.

0.1404 = 14.04% probability of exactly 3 arrivals in a 10-minute interval.

Item d:

This probability is:

[tex]P(X > 3) = 1 - P(X \leq 3)[/tex]

In which:

[tex]P(X \leq 3) = P(X = 0) + P(X = 1) + P(X = 2) + P(X = 3)[/tex]

From item c:

[tex]P(X \leq 3) = 0.0068 + 0.0337 + 0.0842 + 0.1404 = 0.2651[/tex]

Then:

[tex]P(X > 3) = 1 - P(X \leq 3) = 1 - 0.2651 = 0.7349[/tex]

0.7349 = 73.49% probability of more than three arrivals occurring in a 10-minute interval.

A similar problem is given at https://brainly.com/question/16912674

You bicycle along a straight flat road with a safety light attached to one foot. Your bike moves at a speed of 10 km/hr and your foot moves in a circle of radius 24 cm centered 34 cm above the ground, making one revolution per second.
(a) Find parametric equations for x and y which describe the path traced out by the light, where y is distance (in cm) above the ground and x the horizontal distance (in cm) starting position of the center of the circle around which your foot moves. Assuming the light starts cm above the ground, at the front of its rotation.
x(t)=
y(t)=

(b) How fast (in revolutions/sec) would your foot have to be rotating if an observer standing at the side of the road sees the light moving backward?
Rotate at ? revolutions/second.

Answers

Final answer:

The parametric equations similar to a sinusoidal wave are x(t) = 10000t/3600 + 24cos(2πt) and y(t) = 34 + 24sin(2πt). For an observer to see the light moving backward, the foot would have to be making physical revolutions faster than the bike is moving forward, or approximately 7 revolutions/sec.

Explanation:

The light attached to the foot is effectively forming a sinusoidal path as it moves along, creating a circular path while also advancing. Let's start by exploring the parametric equations.

The horizontal position (x) will be a combination of the distance traveled by the bike in time t (which is 10 km/hr * t converted to cm/sec) and the horizontal projection of the circular motion of the foot. The vertical position (y) will be a combination of the base height above the ground and the vertical projection of the circular motion of the foot.

So we have:

x(t) = 10000t/3600 + 24cos(2πt)

y(t) = 34 + 24sin(2πt)>

For your foot to appear to move backward from the perspective of an observer, the foot would have to move faster than the bicycle. This could be calculated by the ratio of bike speed to circumference of rotation. The rotation speed needs to at least meet this ratio.

Rotation speed = 10km/hr / (2π * 0.24m) = ~7 revolutions/sec

Learn more about Physics of cycling here:

https://brainly.com/question/35869557

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suppose you have 3 bags containing only apples and oranges. bag a has 2 apples and 4 oranges, bag b has 8 apples and 4 oranges, and bag c has 1 apple and 3 oranges. you pick 1 fruit (at random) from each bag. a) what is the probability that you picked exactly 2 apples? b) suppose you picked 2 apples but forgot which bag they came from. what is the probability that you picked an apple from bag a?

Answers

Answer:

Step-by-step explanation:

There are three bags

Bag A

2apples and 4 oranges

P(A¹)=2/6

P(A¹)=⅓

P(O¹)=4/6

P(O¹)=⅔

Bag B

8 apples and 4 oranges

P(A²)=8/12

P(A²)=⅔

P(O²)=4/12

P(O²)=⅓

Bag C

1 apple and 3 oranges

P(A³)=¼

P(O³)=¾

Note

P(A¹) means probability of Apple in bag A

P(A²) means probability of Apple in bag B

P(A³) means probability of Apple in bag C

P(O¹) means probability of oranges in bag A.

P(O²) means probability of oranges in bag B.

P(O³) means probability of oranges in bag C.

a. The probability of picking exactly two apples can be analyzed as

Picking apple in bag A and picking apple in bag B and picking orange in bag C or picking apple in bag A and picking orange in bag B and picking apple in bag C or picking orange in bag A and picking apple in bag B and picking apple in bag C.

Then,

P(exactly two apples)=P(A¹ n A² n O³) + P(A¹ n O² n A³) + P(O¹ n A² n A³)

Since they are mutually exclusive

Then,

P(exactly two apples) =

P(A¹) P(A²)P(O³) + P(A¹)P(O²)P(A³) + P(O¹) P(A²) P(A³)

P(exactly two apples) =

(⅓×⅔×¾)+(⅓×⅓×¼)+(⅔×⅔¼)

P(exactly two apples)=1/6 +1/36 +1/9

P(exactly two apples)= 11/36

b. Probability that an apple comes from Bag A out of the two apple will be Picking apple in bag A and picking apple in bag B and picking orange in bag C or picking apple in bag A and picking orange in bag B and picking apple in bag C.

P(an apple belongs to bag A)=P(A¹ n A² n O³) + P(A¹ n O² n A³)

Since they are mutually exclusive

Then,

P(an apple belongs to bag A) =

P(A¹) P(A²)P(O³) + P(A¹)P(O²)P(A³)

P(an apple belongs to bag A) =

(⅓×⅔×¾)+(⅓×⅓×¼)

P(an apple belongs to bag A)=1/6 +1/36

P(an apple belongs to bag A)= 7/36

The alkalinity level of water specimens collected from the Han River in Seoul, Korea, has a mean of 50 milligrams per liter and a standard deviation of 3.2 milligrams per liter. (Environmental Science & Engineering, Sept. 1, 2000.) Assume the distribution of alkalinity levels is approximately normal and find the probability that a water specimen collected from the river has an alkalinity level a. exceeding 45 milligrams per liter. b. below 55 milligrams per liter. c. between 48 and 52 milligrams per liter.

Answers

Answer:

a) 94.06% probability that a water specimen collected from the river has an alkalinity level exceeding 45 milligrams per liter.

b) 94.06% probability that a water specimen collected from the river has an alkalinity level below 55 milligrams per liter.

c) 50.98% probability that a water specimen collected from the river has an alkalinity level between 48 and 52 milligrams per liter.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

[tex]\mu = 50, \sigma = 3.2[/tex]

a. exceeding 45 milligrams per liter.

This probability is 1 subtracted by the pvalue of Z when X = 45. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{45 - 50}{3.2}[/tex]

[tex]Z = -1.56[/tex]

[tex]Z = -1.56[/tex] has a pvalue of 0.0594.

1 - 0.0594 = 0.9406

94.06% probability that a water specimen collected from the river has an alkalinity level exceeding 45 milligrams per liter.

b. below 55 milligrams per liter.

This probability is the pvalue of Z when X = 55.

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{55 - 50}{3.2}[/tex]

[tex]Z = 1.56[/tex]

[tex]Z = 1.56[/tex] has a pvalue of 0.9604.

94.06% probability that a water specimen collected from the river has an alkalinity level below 55 milligrams per liter.

c. between 48 and 52 milligrams per liter.

This is the pvalue of Z when X = 52 subtracted by the pvalue of Z when X = 48. So

X = 52

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{52 - 50}{3.2}[/tex]

[tex]Z = 0.69[/tex]

[tex]Z = 0.69[/tex] has a pvalue of 0.7549

X = 48

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{48 - 50}{3.2}[/tex]

[tex]Z = -0.69[/tex]

[tex]Z = -0.69[/tex] has a pvalue of 0.2451

0.7549 - 0.2451 = 0.5098

50.98% probability that a water specimen collected from the river has an alkalinity level between 48 and 52 milligrams per liter.

The probabilities are calculated using the normal distribution properties: exceeding 45 mg/L is approximately 0.9406, below 55 mg/L is approximately 0.9406, and between 48 and 52 mg/L is approximately 0.4678.

a) To find the probability that the alkalinity level exceeds 45 milligrams per liter, we can use the standard normal distribution with the given mean (50 mg/L) and standard deviation (3.2 mg/L). First, we need to calculate the z-score for 45 mg/L:

z = 45 - 50/3.2 = -1.5625

Then, we find the probability of the alkalinity level exceeding 45 mg/L by finding the area to the right of this z-score in the standard normal distribution. Using a standard normal table or calculator, we find this probability to be approximately 0.9406.

b) Similarly, to find the probability that the alkalinity level is below 55 milligrams per liter, we calculate the z-score for 55 mg/L:

[tex]\[ z = \frac{55 - 50}{3.2} = 1.5625 \][/tex]

Then, we find the probability of the alkalinity level being below 55 mg/L by finding the area to the left of this z-score in the standard normal distribution. Using a standard normal table or calculator, we find this probability to be approximately 0.9406.

c) To find the probability that the alkalinity level is between 48 and 52 milligrams per liter, we first calculate the z-scores for these values:

z₁ = 48-50/3.2 = -0.625

z₂ = 52-50/3.2 = 0.625

Then, we find the area between these two z-scores in the standard normal distribution, which represents the probability of the alkalinity level being between 48 and 52 mg/L. Using a standard normal table or calculator, we find this probability to be approximately 0.3146.

In conclusion:

Probability exceeding 45 mg/L: ≈ 0.9406Probability below 55 mg/L: ≈ 0.9406Probability between 48 and 52 mg/L: ≈ 0.4678.

Use the​ power-reducing formulas to rewrite the expression as an equivalent expression that does not contain powers of trigonometric functions greater than 1. 19 sine Superscript 4 Baseline x

Answers

Answer:

Answer is attached

Final answer:

The power-reducing formulas are used twice to rewrite 19sin^4(x) without trigonometric powers greater than 1, resulting in 19(3/8 - (1/2)cos(2x) + (1/8)cos(4x)).

Explanation:

The problem requires using power-reducing formulas to rewrite the expression 19 sine to the power of 4 of x (19 sin4x) as an equivalent expression that does not contain powers of trigonometric functions greater than 1. The power-reducing formula for sin2a is sin2a = (1 - cos(2a)) / 2. We must apply this formula twice because we have sin4x.

First step:

sin4x = (sin2x)2sin2x = (1 - cos(2x)) / 2 (using power-reducing formula)sin4x = ((1 - cos(2x)) / 2)2

Second step:

sin4x = (1 - 2cos(2x) + cos2(2x)) / 4Apply power-reducing formula again to cos2(2x)cos2(2x) = (1 + cos(4x)) / 2sin4x = (1 - 2cos(2x) + (1 + cos(4x)) / 2) / 4Simplify the expressionsin4x = (1/4 - (1/2)cos(2x) + 1/8 + (1/8)cos(4x))sin4x = (3/8 - (1/2)cos(2x) + (1/8)cos(4x))

Therefore, the final expression without powers greater than 1 is 19 multiplied by (3/8 - (1/2)cos(2x) + (1/8)cos(4x)), or

19sin4x = 19(3/8 - (1/2)cos(2x) + (1/8)cos(4x))

A particular fruit's weights are normally distributed, with a mean of 239 grams and a standard deviation of 23 grams. If you pick 25 fruits at random, then 10% of the time, their mean weight will be greater than how many grams

Answers

Answer:

[tex]z=1.28<\frac{a-239}{4.6}[/tex]

And if we solve for a we got

[tex]a=239 +1.28*4.6=244.89[/tex]

So the value of height that separates the bottom 90% of data from the top 10% is 244.89.  

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".  

Solution to the problem:

Let X the random variable that represent the heights of a population, and for this case we know the distribution for X is given by:

[tex]X \sim N(239,23)[/tex]  

Where [tex]\mu=239[/tex] and [tex]\sigma=23[/tex]

Since the distribution for X is normal then we know that the distribution for the sample mean [tex]\bar X[/tex] is given by:

[tex]\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})[/tex]

And we are interested on a value a such that:

[tex]P(\bar X>a)=0.10[/tex]   (a)

[tex]P(\bar X<a)=0.90[/tex]   (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.  

As we can see on the figure attached the z value that satisfy the condition with 0.90 of the area on the left and 0.1 of the area on the right it's z=1.28. On this case P(Z<1.28)=0.9 and P(z>1.28)=0.1

If we use condition (b) from previous we have this:

[tex]P(\bar X<a)=P(\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n}}}<\frac{a-\mu}{\frac{\sigma}{\sqrt{n}}})=0.9[/tex]  

[tex]P(z<\frac{a-\mu}{\frac{\sigma}{\sqrt{n}}})=0.9[/tex]

But we know which value of z satisfy the previous equation so then we can do this:

[tex]z=1.28<\frac{a-239}{4.6}[/tex]

And if we solve for a we got

[tex]a=239 +1.28*4.6=244.89[/tex]

So the value of height that separates the bottom 90% of data from the top 10% is 244.89.  

An ANOVA procedure is used for data obtained from four populations. Four samples, each comprised of 30 observations, were taken from the four populations. The numerator and denominator (respectively) degrees of freedom for the critical value of F are


A. 3 and 30
B. 4 and 30
C. 3 and 119
D. 3 and 116

Answers

Answer:

D. 3 and 116

Step-by-step explanation:

d.f.N = k - 1 (numerator degrees of freedom) = 4 - 1 = 3

N = 4 × 30 = 120

d.f.D = N - k (denominator degrees of freedom) = 120 - 4 =116

Final answer:

In ANOVA, the degrees of freedom for the numerator is the number of groups minus one, and for the denominator, it is the total number of observations minus the number of groups. Thus, the correct answer is 3 and 116 for the numerator and denominator degrees of freedom.

Explanation:

The ANOVA procedure is used to compare means across multiple populations to see if there's a significant difference. With four populations and samples of 30 observations each, we are working with an F distribution in the framework of an ANOVA analysis.

The degrees of freedom for the numerator in ANOVA is calculated as the number of groups minus one. Therefore, for four populations, it is 4 - 1 = 3. The degrees of freedom for the denominator is the total number of observations minus the number of groups. Thus, with four samples of 30, the total number of observations is 4 × 30 = 120, minus the number of groups gives us 120 - 4 = 116. So, the answer is 3 for the numerator and 116 for the denominator.

Hence, the correct choice is D. 3 and 116 for the numerator and denominator degrees of freedom, respectively.

"According to contractarian logic, we should be willing to make concessions to others if they agree to make comparable and reciprocal concessions, with the overall result being that everyone gets a desired benefit with an acceptable minimum of sacrifice on each side. Please identify, and briefly analyze, a situation or scenario that illustrates this principle. "

Answers

Answer:In a couple with a newborn baby at home, to take turns on feeding the baby at night.

Step-by-step explanation: Here both parents are willing to sacrifice a few minutes, if not hours of sleeptime with the promise to be allowed to rest the next time the baby needs to be fed. There is no certainty in how long it will take for the baby to go back to sleep or how long it will be for the baby to be awake again, but the chances are the same for both parents, so they both agree to take care of the child one at a time with the promise to be in turns, this is an example of contractarian logic.

Final answer:

Contractarian logic is exemplified in international trade agreements where nations mutually lower tariffs under the expectation of reciprocal actions, demonstrating the principle of reciprocity and mutual advantage.

Explanation:

According to contractarian logic, we should be willing to make concessions to others if they agree to make comparable and reciprocal concessions, leading to a situation where everyone benefits with a minimal level of sacrifice. A classic example illustrating this principle is international trade agreements. Nations often agree to lower tariffs and grant each other favorable trade terms under the condition that the other nation reciprocates. These agreements are founded on the expectation that both sides will adhere to the agreements, benefiting both by expanding their markets and reducing costs for consumers. Here, the benefit is mutual economic growth, and the sacrifice might involve foregoing the protection of certain domestic industries in the interest of broader gains. This scenario mirrors the foundational ideas of social contract theory where rational, self-interested agents come together to agree on a set of rules or actions that benefit all parties involved, thereby demonstrating the principle of reciprocity and mutual advantage that is central to contractarian logic.

The Supreme Court recently ruled that a police department in Florida did not violate any rights of privacy when a police helicopter flew over the backyard of a suspected drug dealer and noticed marijuana growing on his property. Many people, including groups like the Anti-Common Logic Union, felt that the suspect's right to privacy outweighed the police department's need to protect the public at large. The simple idea of sacrificing a right to serve a greater good should be allowed in certain cases. In this particular case the danger to the public wasn't extremely large; marijuana is probably less dangerous than regular beer. But anything could have been in that backyard—a load of cocaine, an illegal stockpile of weapons, or other major threats to society.

Answers

Final answer:

The question addresses the complex balance between individual privacy rights and law enforcement's authority to conduct searches, as protected and outlined by the Fourth Amendment. The Supreme Court has ruled on various cases that determine the scope of these rights, including exceptions that allow warrantless searches under specific circumstances. The ongoing evolution of privacy rights aligns with societal and technological changes, demanding constant legal reassessment.

Explanation:

Understanding Privacy Rights and Law Enforcement Searches

The case you are referring to touches on the complexities of privacy rights within the scope of law enforcement. Specifically, it deals with the interpretation of the Fourth Amendment which protects citizens from unreasonable searches and seizures. This protection extends to government actions and sets boundaries for police searches to respect individual privacy. However, there have been exceptions carved out that enable law enforcement to operate under certain circumstances without a warrant. This issue becomes even more complex with modern technology like drones, which can bypass traditional expectations of privacy.

For instance, the reasonable expectation of privacy is a key legal concept that dictates whether particular searches or seizures may be deemed reasonable without a warrant. Situations such as being visible from public airspaces or instances of exigent circumstances can fall outside the protections intended by the Fourth Amendment. Moreover, the amendment necessitates a search warrant to be obtained before conducting most searches or seizures. Nevertheless, Supreme Court rulings have established that there are scenarios where the warrant requirement is not applicable, such as when the items in question are in plain view or consent to search is given.

Privacy rights continue to evolve with societal changes and technological advancements. Courts and lawmakers constantly revisit and redefine the levels of privacy individuals can expect, balancing this against the interests of law enforcement and public safety. Matters such as the decriminalization of marijuana at state levels and exceptions to privacy within educational settings reflect the continuing dialogue and legal interpretation surrounding privacy rights and enforcement powers.

At one SAT test site students taking the test for a second time volunteered to inhale supplemental oxygen for 10 minutes before the test. In fact, some received oxygen, but others (randomly assigned) were given just normal air. Test results showed that 42 of 66 students who breathed oxygen improved their SAT scores, compared to only 35 of 63 students who did not get the oxygen. Which procedure should we use to see if there is evidence that breathing extra oxygen can help test-takers think more clearly

Answers

the correct choice is:

E. 2-proportion Z-test

To determine if there is evidence that breathing extra oxygen can help test-takers think more clearly, we should use the 2-proportion Z-test.

This test is appropriate because we are comparing two proportions (the proportion of students who improved their SAT scores among those who breathed oxygen and those who did not) from two independent groups (students who received oxygen and those who did not).

Therefore, the correct choice is:

E. 2-proportion Z-test

The probable question maybe:

At one SAT test site students taking the test for a second time volunteered to inhale supplemental oxygen for 10 minutes before the test. In fact, some received oxygen but others (randomly assigned) were given just normal air. Test results showed that 42 of 66 students who breathed oxygen improved their SAT scores, compared to only 35 of 63 students who did not get the oxygen Which procedure should we use to see if there is evidence that breathing extra oxygen can help test-takers think more clearly?

A. 1-proportion 2-test

B matched pairs t-test

C 2-sample t-test

D. 1-sample t-test

E. 2-proportion Z-test

A chi-square test for independence should be used to analyze the effect of breathing extra oxygen on SAT score improvements, by comparing observed frequencies of score improvements with expected frequencies under the null hypothesis.

To determine if there is evidence that breathing extra oxygen can help test-takers think more clearly, a statistical test of significance is appropriate. In this scenario, you would typically use a chi-square test for independence to see if there is a significant association between the treatment (oxygen vs. normal air) and the outcome (improvement in SAT scores). The chi-square test compares the observed frequencies of events (here, the number of students who improved) with the frequencies we would expect to see if there were no association between the treatment and the outcome.

The procedure involves calculating a chi-square statistic, which reflects how far the observed frequencies are from the expected frequencies assuming the null hypothesis is true (no effect of breathing extra oxygen). If the resulting p-value is less than the chosen significance level (commonly 0.05), we can reject the null hypothesis and conclude that there is evidence to suggest a relationship between breathing extra oxygen and improved SAT scores.

The method of tree ring dating gave the following years A.D. for an archaeological excavation site. Assume that the population of x values has an approximately normal distribution. 1313 1243 1271 1313 1268 1316 1275 1317 1275 (a) Use a calculator with mean and standard deviation keys to find the sample mean year x and sample standard deviation s. (Round your answers to the nearest whole number.) x

Answers

Answer:

[tex] \bar X = \frac{\sum_{i=1}^n X_i}{n}[/tex]

And replacing we got:

[tex]\bar X = \frac{1313+1243+1271+1313+1268+1316+1275+1317+1275}{9}=1287.89 \approx 1288[/tex]

In order to find the sample deviation we can use this formula:

[tex]s= \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}[/tex]

s= \sqrt{\frac{(1313-1287.89)^2 +(1243-1287.89)^2 +(1271-1287.89)^2 +(1313-1287.89)^2 +(1268-1287.89)^2 + (1316-1287.89)^2 +(1275-1287.89)^2 +(1317-1287.89)^2 +(1275-1287.89)^2}{9-1}}= 27.218 \approx 27

Step-by-step explanation:

For this case we have the following data given:

1313 1243 1271 1313 1268 1316 1275 1317 1275

In order to calculate the sample mean we can use the following formula:

[tex] \bar X = \frac{\sum_{i=1}^n X_i}{n}[/tex]

And replacing we got:

[tex]\bar X = \frac{1313+1243+1271+1313+1268+1316+1275+1317+1275}{9}=1287.89 \approx 1288[/tex]In order to find the sample deviation we can use this formula:

[tex]s= \sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}[/tex]

And replacing we have:

s= \sqrt{\frac{(1313-1287.89)^2 +(1243-1287.89)^2 +(1271-1287.89)^2 +(1313-1287.89)^2 +(1268-1287.89)^2 + (1316-1287.89)^2 +(1275-1287.89)^2 +(1317-1287.89)^2 +(1275-1287.89)^2}{9-1}}= 27.218 \approx 27

What is the slope of the line that passes through the points (1,7) and (-4,-8)?

Answers

Answer:

The slope of the line that passes through the points (1,7) and (-4,-8) is 3.

Step-by-step explanation:

The equation of a line has the following format.

[tex]y = ax + b[/tex]

In which a is the slope.

Passes through the point (1,7)

When [tex]x = 1, y = 7[/tex]

So

[tex]y = ax + b[/tex]

[tex]7 = a + b[/tex]

Passes through the point (-4, -8)

When [tex]x = -4, y = -8[/tex]

So

[tex]y = ax + b[/tex]

[tex]-8 = -4a + b[/tex]

We have to solve the following system

[tex]a + b = 7[/tex]

[tex]-4a + b = -8[/tex]

We want to find a.

From the first equation

[tex]b = 7 - a[/tex]

Replacing in the second equation

[tex]-4a + b = -8[/tex]

[tex]-4a + 7 - a = -8[/tex]

[tex]-5a = -15[/tex]

[tex]5a = 15[/tex]

[tex]a = \frac{15}{5}[/tex]

[tex]a = 3[/tex]

The slope of the line that passes through the points (1,7) and (-4,-8) is 3.

A random sample of 8 recent college graduates found that starting salaries for architects in New York City had a mean of $42,653 and a standard deviation of $9,114. There are no outliers in the sample data set. Construct a 95% confidence interval for the average starting salary of all architects in the city.

A. (35222.41, 50083.59)
B. (34506.12, 50799.88)
C. (36337.32, 48968.68)
D. (35032.29, 50273.71)

Answers

Answer:

C. (36337.32, 48968.68)

Step-by-step explanation:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1-0.95}{2} = 0.025[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].

So it is z with a pvalue of [tex]1-0.025 = 0.975[/tex], so [tex]z = 1.96[/tex]

Now, find M as such

[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

[tex]M = 1.96*\frac{9114}{\sqrt{8}} = 6315.68[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 42653 - 6315.68 = 36337.32.

The upper end of the interval is the sample mean added to M. So it is 42653 + 6315.68 = 48968.68.

So the correct answer is:

C. (36337.32, 48968.68)

The correct option is D.

[tex](35032.29,50273.71)[/tex]

Probability Sampling:

Probability sampling is described as a sampling method in which the person or researcher chooses samples from a larger population using a method based on the theory of probability. For the participant, it is necessary to choose a random selection.

Note that margin of Error [tex]E=\frac{t\alpha }{2}\ast \frac{s}{\sqrt{n}} \\[/tex]

Lower Bound [tex]X=\frac{-t\alpha }{2}\ast \frac{s}{\sqrt{n}} \\[/tex]

Upper Bound [tex]X=\frac{+t\alpha }{2}\ast \frac{s}{\sqrt{n}}[/tex]

Where,

[tex]\frac{\alpha }{2}=\frac{\left ( 1-confidence \ level \right )}{2}=0.025\\\frac{t\alpha }{2}=critical \ t \ for \ the \ confidence \ interval=2.364624252[/tex]

[tex]S[/tex]=sample standard deviation[tex]=9114[/tex]

[tex]n[/tex]=sample size[tex]=8[/tex]

[tex]df=n-1=7[/tex]

Thus, the Margin of Error[tex]E=7619.49468[/tex]

Lower bound[tex]=35033.50532[/tex]

Upper bound[tex]=50272.49468[/tex][

Thus, the confidence interval is[tex](35033.50532 \ , 50272.49468 )[/tex]

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Let H be an upper Hessenberg matrix. Show that the flop count for computing the QR decomposition of H is O(n2), assuming that the factor Q is not assembled but left as a product of rotators.

Answers

Answer:

Answer is explained in the attached document

Step-by-step explanation:

Hessenberg matrix- it a special type of square matrix,there there are two subtypes of hessenberg matrix that is upper Hessenberg matrix and lower Hessenberg matrix.

upper Hessenberg matrix:- in this type of matrix  zero entries below the first subdiagonal or in another words square matrix of n\times n is said to be in upper Hessenberg form  if ai,j=0

for all i,j with i>j+1.and upper Hessenberg matrix is called unreduced if all subdiagonal entries are nonzero

lower Hessenberg matrix:-  in this type of matrix  zero entries upper the first subdiagonal,square matrix of n\times n is said to be in lower Hessenberg form  if ai,j=0  for all i,j with j>i+1.and lower Hessenberg matrix is called unreduced if all subdiagonal entries are nonzero.

Using the fixed-time period inventory model, and given an average daily demand of 200 units, 4 days between inventory reviews, 5 days for lead time, 120 units of inventory on hand, a "z" of 1.96, and a standard deviation of demand over the review and lead time of 3 units, which of the following is the order quantity?

A. About 1,086
B.About 1,686
C. About 1,806
D. About 2,206
E. About 2,686

Answers

Answer:

Correct option: B. About 1,686.

Step-by-step explanation:

The formula to compute the order quantity (Q) is:

[tex]Q=(q_{d}\times (I+L))+(z\times\sigma_{I+L})-I_{n}[/tex]

Here

[tex]q_{d}=average\ daily\ semand=200\\I = Inventory\ review\ time=4\\L=lead\ time=5\\\sigma_{I+L}=standard\ deviation\ over\ the\ review\ and\ lead\ time=3\\I_{n}=number\ of\ units\ of\ inventory\ on\ hand=120[/tex]

Compute the order quantity as follows:

[tex]Q=(q_{d}\times (I+L))+(z\times\sigma_{I+L})-I_{n}\\=(200\times(4+5))+(1.96\times 3)-120\\=1800+5.88-120\\=1685.88\\\approx1686[/tex]

Thus, the order quantity was about 1,686.

Is (2,7) a point on the line y=4x-3?

YES OR NO?

Answers

Answer:

mmmm

yesssirrreeee

The primary deliverables from requirements determination include: A. sets of forms, reports, and job descriptions B. transcripts of interviews C. notes from observation and from analysis documents D. All of these

Answers

Answer:

D. All of these

Step-by-step explanation:

Requirements determination is the process of transforming a system's request into more detailed business statement that is clear and precise. It is the beginning sub phase of analysis, so all the given options in the question can be included.

You are given that claims are reported according to a homogeneous Poisson process. Starting from time zero, the expected waiting time until the second claim is three hours. Calculate the standard deviation of the waiting time until the second claim.

Answers

Answer:

1.732

Step-by-step explanation:

You are given that claims are reported according to a homogeneous Poisson process

LetX be the waiting time from 0 to second claim

X is Poisson with averageof 3 hours.

We know in a Poisson distribution the mean = variance

Hence average waiting time = mean = 3

This will also be equal to var(x)

Var(x) = mean of Poisson distribution= 3

Hence standard deviation = square root of variance

=[tex]\sqrt{3} \\=1.732[/tex]

Testing for a Vector Space In Exercises 13–36, determine whether the set, together with the standard operations, is a vector space. If it is not, identify at least one of the ten vector space axioms that fails. 13. M, 4.6 14. M, 15. The a set of all third-degree polynomials 16. The set of all fifth-degree polynomials 17. The set of all first-degree polynomial functions ax, a t 0, whose graphs pass through the origin 18. The set of all first-degree polynomial functions ax + b a, b 0, whose graphs do not pass through the origin 19. The set of all polynomials of degree four or less

Answers

Answer:

Step-by-step explanation:

13. The set M4,6 of all 4x6 matrices is a vector space as it is closed under vector addition as also scalar multiplication. Also the 4x6 zero matrix is in M4,6.

14. The set M1,1 is a singleton, i.e. a 1x1 matrix. It is a vector space for the same reasons as in 13. above.

15. The degree of the zero polynomial is undefined and it is usually treated as a constant (of degree 0). If we treat 0 as a polynomial of degree 0, then the set of all 3rd degree polynomials is not a vector space despite being closed under vector addition and scalar multiplication as it does not contain the zero polynomial.

16. The set of all 5th degree polynomials is not a vector space despite being closed under vector addition and scalar multiplication as it does not contain the zero polynomial.

17. The set of all first degree polynomials ax (a≠0) is not a vector space. If p(x) = ax and q(x) = -ax , then p(x)+q(x) = 0*x which is not in the given set. Hence the set is not closed under vector addition and, therefore, it is not a vector space.

18. The set of all first degree polynomials ax +b (a,b ≠0) is not a vector space. If p(x) = ax +b and q(x) = -ax -b , then p(x)+q(x) = 0*x +0 which is not in the given set. Hence the set is not closed under vector addition and, therefore, it is not a vector space.

19. The set P4 of all polynomials of degree 4 or less isa vector space. If p(x) = a1x4+a2 x3+a3x2+a4x+a5 and q(x) = b1x4+b2 x3+b3x2+b4x+b5 are 2 arbitrary elements of P4, then p(x)+q(x)is in P4. Similarly, αp(x) is in P4 for any arbitrat scalar α. Hence, P4 is closed under vector addition and scalar multiplication. Also, the 0 polynomial is in P4. Hence P4 is a vector space.

Final answer:

A set forms a vector space if it meets all ten vector space axioms. For instance, a set of first-degree polynomial functions ax + b, where a, and b are non-zero and whose graphs do not pass through the origin, fails to meet vector space axiom for closure under addition. On the other hand, the set of all third-degree polynomials is a vector space as it satisfies all ten vector space axioms.

Explanation:

To determine whether a set combined with standard operations forms a vector space, it must satisfy ten vector space axioms. These axioms include requirements regarding the addition and scalar multiplication of vectors.

To illustrate, let's look at the set of all first-degree polynomial functions ax + b, with a, b ≠ 0, whose graphs do not pass through the origin. By definition, vectors in a vector space should be closed under addition, i.e., if you add any two vectors together, you should get another vector in the set. However, if we add two such functions together ax + b + cx + d = (a+c)x + (b+d), the resulting function will pass through the origin only if (b+d)=0. But given that b and d are non-zero, the sum will not yield a first-degree polynomial that passes through the origin. Therefore, this set fails to meet the vector space axiom for closure under addition.

On the other hand, the set of all third-degree polynomials will be a vector space as it adheres to all the ten axioms. For example, if two polynomials in the set are added together or multiplied by a scalar, the resultant is still a third-degree polynomial which means it still belongs to the set.

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1. Hank is an intelligent student and usually makes good grades, provided that he can review the course material the night before the test. For tomorrow's test, Hank is faced with a small problem: His fraternity brothers are having an all-night party in which he would like to participate. Hank has three options: a1 - party all night: 2-divide the night equally between studying and partying: 3 - study all night. Tomorrow's exam can be easy (s1), moderate (S2) or tough (53), depending on the professor's unpredictable mood. Hank anticipates the following scores:

S1 S2 S3
a1 85 60 40
a2 92 85 81
a3 100 88 82

(a) Recommend a course of action for Hank based on each of the four criteria of decisions under uncertainty.
(b) Suppose that Hank is more interested in the letter grade he will get. The dividing scores for the passing letter grades A to Dare 90, 80, 70 and 60, respectively. What should the decision/s be?

Answers

Answer and Step-by-step explanation:

The answer is attached below

The expected pay-off for a₃ is maximum. Then the decision a₃ (study all night) is considered.

What are statistics?

Statistics is the study of collection, analysis, interpretation, and presentation of data or to discipline to collect, summarise the data.

Hank is an intelligent student and usually makes good grades, provided that he can review the course material the night before the test.

For tomorrow's test, Hank is faced with a small problem: His fraternity brothers are having an all-night party in which he would like to participate.

Hank has three options:

a₁ - party all night

a₂ - divide the night equally between studying and partying

a₃ - study all night

Tomorrow's exam can be easy (S₁), moderate (S₂) or tough (S₃), depending on the professor's unpredictable mood. Hank anticipates the following scores:

             S₁               S₂             S₃

a₁          85              60             40

a₂         92              85             81

a₃        100              88             82

Decision under uncertainty

1.  For maximum criterion when the exam is tough.

a₁  = 40, a₂ = 81, and a₃ = 82

Since 82 is the maximum out of the minimum. Then the optional action is a₃ (study all night).

2.  For maximum criterion when the exam is easy.

a₁  = 85, a₂ = 92, and a₃ = 100

Since 82 is the maximum out of the maximum. Then the optional action is a₃ (study all night).

3.  Regret criterion

First, find the regret matrix.

             S₁               S₂             S₃         Max. regret

a₁          15              28             42                 42

a₂          8                3                1                   8

a₃          0                0               0                   0

From the maximum regret column, we find that the regret corresponding to the course of action is a₃ is minimum. Therefore, decision a₃ (study all night) will be considered.

4.  Laplace criterion

The probability of occurrence is 1/3.

Therefore, the expected pay-off for each decision will be

E(a₁) = 61.67, E(a₂) = 86, and E(a₃) = 90

Therefore, the expected pay-off for a₃ is maximum.

Thus, decision a₃ (study all night) is considered.

More about the statistics link is given below.

https://brainly.com/question/10951564

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