Answer:
0.62 = 62% probability that a U.S. adult selected at random thinks the occupation of firefighter has very great prestige.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
Desired outcomes:
Adults who consider the occupation of firefighter to have very great prestige. So the number of desired outcomes is [tex]D = 627[/tex]
Total outcomes.
All adults sampled. So [tex]T = 1010[/tex]
Probability:
[tex]P = \frac{D}{T} = \frac{627}{1010} = 0.62[/tex]
0.62 = 62% probability that a U.S. adult selected at random thinks the occupation of firefighter has very great prestige.
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.
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.
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
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.
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
Answer:
Answer is attached
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)2Second 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))
You are certain to get a heart comma diamond comma club comma or spade when selecting cards from a shuffled deck. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive
Answer:
Probability = 1
Step-by-step explanation:
The number of each type of card described in the question from within a full deck of cards is as follows;
Hearts = 13
Clubs = 13
Diamonds = 13
Spades = 13
These add up to a total of 52 cards. Since a deck only has 52 cards, these make up all the cards in the deck.
Since the probability of taking out a card from these four suits is going to be as follows:
Probability = number of ways we can take out a corresponding suit card / total number of cards
Probability = 52 / 52
Probability = 1
Thus, we can see that the probability of taking out a card belonging to one of the four suits (heart,diamond,club,spade) is 1.
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
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.
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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?
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
A drawer contains 4 different pairs of gloves. Suppose we choose 3 gloves randomly, what is the probability that there is no matching pair?
Answer:
The probability that there is no matching pair is 4/7 = 0.5714286.
Step-by-step explanation:
For the first glove we have no restrictions. For the second glove, we have 6 gloves that works for us and 1 that doesnt work (the one that matches the first glove), hence we have 6 possibilities out of 7. Once we pick a good second glove, for the last glove, we only have 4 cases that doesnt match the other two pairs, out of 6 total. This means that the probability that there is no matching pair is 6/7*4/6 = 4/7.
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.
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
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(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?
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
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.
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.
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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.
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
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.
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
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
"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. "
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.
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)
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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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.
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]
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
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.
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
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%.
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.
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.
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
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.
A blood bank asserts that a person with type O blood and a negative Rh factor (Rh?) can donate blood to any person with any blood type. Their data show that 43% of people have type O blood and 19% of people have Rh? factor; 45% of people have type O or Rh? factor.1.) Find the probability that a person has both type O blood and the Rh? factor.2.) Find the probability that a person does NOT have both type O blood and the Rh? factor.
Answer:P(O)UP(Rh)=17% while n(O)U(Rh) complement is 87%
Step-by-step explanation:
Since 43% represent those blood group O and 19% those with blood Rh,summing up gives 62%
Subtract 45% from 62%=17%
The probability that the person doesn't have either blood group is1 -17%=83%
Answer:
The probability that a person has a positive Rh factor given that he/she has type O blood is 82 percent.
There is a greater probability for a person to have a Positive Rh factor given type A blood than a person to have a positive Rh factor given type O blood.
Please help!!!!!! I’ll mark you as brainliest if correct
Answer: 771,243
Step-by-step explanation:
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?
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
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 .
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
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
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.
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
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.
A 2005 survey found that 7% of teenagers (ages 13 to 17) suffer from an extreme fear of spiders (arachnophobia). At a summer camp there are 10 teenagers sleeping in each tent. Assume that these 10 teenagers are independent of each other. What is the probability that at least one of them suffers from arachnophobia
Answer:
Probability that at least one of them suffers from arachnophobia is 0.5160.
Step-by-step explanation:
We are given that a 2005 survey found that 7% of teenagers (ages 13 to 17) suffer from an extreme fear of spiders (arachnophobia).
Also, At a summer camp there are 10 teenagers sleeping in each tent.
Firstly, the binomial probability is given by;
[tex]P(X=r) =\binom{n}{r}p^{r}(1-p)^{n-r} for x = 0,1,2,3,....[/tex]
where, n = number of trials(teenagers) taken = 10
r = number of successes = at least one
p = probability of success and success in our question is % of
the teenagers suffering from arachnophobia, i.e. 7%.
Let X = Number of teenagers suffering from arachnophobia
So, X ~ [tex]Binom(n= 10,p=0.07)[/tex]
So, probability that at least one of them suffers from arachnophobia
= P(X >= 1) = 1 - probability that none of them suffers from arachnophobia
= 1 - P(X = 0) = 1 - [tex]\binom{10}{0}0.07^{0}(1-0.07)^{10-0}[/tex]
= 1 - (1 * 1 * [tex]0.93^{10}[/tex] ) = 1 - 0.484 = 0.5160 .
Therefore, Probability that at least one of them suffers from arachnophobia is 0.5160 .
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?
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.
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?
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
What is the slope of the line that passes through the points (1,7) and (-4,-8)?
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.
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?
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