According to a recent poll 53% of Americans would vote for the incumbent president. If a random sample of 100 people results in 40% who would vote for the incumbent, test whether the claim that the actual percentage is different from 53% is supported or not supported.

(1) State the null hypothesis.
(2) State the alternative hypothesis.
(3) What is the test statistic used for the test (z or t)?
(4) State the significance or alpha (α) level?

Answers

Answer 1

Answer:

1) Null hypothesis:[tex]p=0.53[/tex]  

2)Alternative hypothesis:[tex]p \neq 0.53[/tex]  

3) [tex]z=\frac{0.4 -0.53}{\sqrt{\frac{0.53(1-0.53)}{100}}}=-2.605[/tex]  

4) We assume that [tex]\alpha=0.05[/tex]

[tex]p_v =2*P(z<-2.605)=0.0092[/tex]  

So the p value obtained was a very low value and using the significance level given [tex]\alpha=0.05[/tex] we have [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of people who would vote for the incumbent is different from 0.53.  

Step-by-step explanation:

Data given and notation  

n=100 represent the random sample taken

[tex]\hat p=0.4[/tex] estimated proportion of people who would vote for the incumbent

[tex]p_o=0.53[/tex] is the value that we want to test

[tex]\alpha=0.05[/tex] represent the significance level  (assumed)

Confidence=95% or 0.95  (Assumed)

z would represent the statistic (variable of interest)

[tex]p_v[/tex] represent the p value (variable of interest)  

Concepts and formulas to use  

We need to conduct a hypothesis in order to test the claim that the true proportion is 0.53 or not.:  

1) Null hypothesis:[tex]p=0.53[/tex]  

2)Alternative hypothesis:[tex]p \neq 0.53[/tex]  

When we conduct a proportion test we need to use the z statistic, and the is given by:  

[tex]z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}[/tex] (1)  

The One-Sample Proportion Test is used to assess whether a population proportion [tex]\hat p[/tex] is significantly different from a hypothesized value [tex]p_o[/tex].

3) Calculate the statistic  

Since we have all the info requires we can replace in formula (1) like this:  

[tex]z=\frac{0.4 -0.53}{\sqrt{\frac{0.53(1-0.53)}{100}}}=-2.605[/tex]  

4) Statistical decision  

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.  

The significance level assumed [tex]\alpha=0.05[/tex]. The next step would be calculate the p value for this test.  

Since is a bilateral test the p value would be:  

[tex]p_v =2*P(z<-2.605)=0.0092[/tex]  

So the p value obtained was a very low value and using the significance level given [tex]\alpha=0.05[/tex] we have [tex]p_v<\alpha[/tex] so we can conclude that we have enough evidence to reject the null hypothesis, and we can said that at 5% of significance the proportion of people who would vote for the incumbent is different from 0.53 .  


Related Questions

Consider the baggage check-in process of a small airline. Check-in data indicate that from 9 a.m. to 10 a.m., 220 passengers checked in. Moreover, based on counting the number of passengers waiting in line, airport management found that the average number of passengers waiting for check-in was 27.?How long did the average passenger have to wait in line?

Answers

Answer:

The passengers have an average of 8.15 minutes to wait in line

Step-by-step explanation:

Using Little's law

Average Inventory = Average Flow Time * Average Flow Rate

Average Inventory = 220 passengers

Average Flow Rate = 27

Average Flow time =?

So,

220 = Average Flow Time * 27

Average Flow Time = 220/27

Average Flow Time = 8.14814814814

Average Flow Time = 8.15 --------- Approximated

So the average wait time for a passenger is 8.15 minutes

Final answer:

The average passenger had to wait in line for approximately 0.123 minutes.

Explanation:

To find the average waiting time, we need to divide the total waiting time by the number of passengers. The total waiting time can be calculated by multiplying the average number of passengers waiting (27) by the time period (1 hour). The average waiting time is then found by dividing this total waiting time by the number of passengers checked in (220).

Average waiting time = (Average number of passengers waiting × Time period) / Number of passengers checked in

First, find the total waiting time: Total waiting time = 27 × 1 = 27 minutesNext, find the average waiting time: Average waiting time = 27 / 220 = 0.123 minutes (approximately)

Therefore, the average passenger had to wait in line for approximately 0.123 minutes.

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A force of 10 lb is required to hold a spring stretched 2 in. beyond its natural length. How much work W is done in stretching it from its natural length to 5 in. beyond its natural length?

Answers

Answer:

Work done will be equal to 5.2059 lb-ft

Step-by-step explanation:

We have given force F = 10 lb

Spring is stretched to 2 in

So x = 2 in

As 1 inch = 0.0833 feet

So 2 inch = 2×0.0833 = 0.1666 feet

From hook's law we know that F = Kx , here K is spring constant and x is spring elongation

So [tex]10=K\times 0.1666[/tex]

K = 60.024 lb/feet

Now new elongation x = 5 in

So 5 in = 5×0.0833 = 0.4165 feet

Work done is given by [tex]W=\frac{1}{2}Kx^2[/tex]

So [tex]W=\frac{1}{2}\times 60.02\times 0.4165^2=5.205lb-ft[/tex]

So work done will be equal to 5.2059 lb-ft

Recursive definitions for subsets of binary strings.Give a recursive definition for the specified subset of the binary strings. A string r should be in the recursively defined set if and only if r has the property described. The set S is the set of all binary strings that are palindromes. A string is a palindrome if it is equal to its reverse. For example, 0110 and 11011 are both palindromes.

Answers

Answer:

Step-by-step explanation:

A binary string with 2n+1 number of zeros, then you can get a binary string with 2n(+1)+1 = 2n+3 number of zeros either by adding 2 zeros or 2 1's at any of the available 2n+2 positions. Way of making each of these two choices are (2n+2)22. So, basically if b2n+12n+1 is the number of binary string with 2n+1 zeros then your

b2n+32n+3 = 2 (2n+2)22 b2n+12n+1

your second case is basically the fact that if you have string of length n ending with zero than you can the string of length n+1 ending with zero by:

1. Either placing a 1 in available n places (because you can't place it at the end)

2. or by placing a zero in available n+1 places.

0 ϵ P

x ϵ P → 1x ϵ P , x1 ϵ P

x' ϵ P,x'' ϵ P → xx'x''ϵ P

A recursive definition for the set of binary string palindromes starts with the base cases '0' and '1'. Other palindromes can be obtained by nesting a palindrome between '0' and '0' or '1' and '1'.

A recursive definition for the set S, consisting of all binary strings that are palindromes, would be defined by two rules:

For the base cases, both '0' and '1' are in S. This covers the palindromes of length 1.

The inductive step would be: If 'P' is a string in S, then both '0P0' and '1P1' are in S. This allows us to generate palindromes of increasing lengths all the way to infinity.

By this definition, a string is a palindrome if it is the same when read from left to right and right to left. It starts with the simplest cases (single digit palindromes) and then defines how to build larger examples based on smaller ones.

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In a box there are two coins: a standard coin with head and tail and a 2-headed coin. You randomly pick one of the coins, toss it and see a head. What is the probability that the other side of this coin is a head?

Answers

Answer:

Probability that the other side of this coin is a head = 0.5

Step-by-step explanation:

Given that there are two coins: a standard coin with head and tail and a 2 - headed coin.

When tossing a randomly chosen coin once the sample space obtained will be :

Head of a standard coin.Tail of a standard coin.Front Head side of 2-headed coin.Back Head side of 2-headed coin.

Now since we have to find the probability that the other side of this coin which is tossed is also a head which means probability of selecting a 2-headed coin.

From the above cases there are two outcomes which are in favour from total of four outcomes;

Hence, Probability that the other side of this coin is a head = [tex]\frac{1}{2}[/tex] = 0.5 .

special deck of cards has 20 cards. Nine are green, seven are blue, and four are red. When a card is picked, the color of it is recorded. An experiment consists of first picking a card and then tossing a coin. A. How many elements are there in the sample space? B. Let A be the event that a red card is picked first, followed by landing a tail on the coin toss. P(A) = Present your answer as a decimal number to 1 decimal place. C. Let B be the event that a green or blue is picked, followed by landing a tail on the coin toss. Are the events A and B mutually exclusive? D. Let C be the event that a green or red is picked, followed by landing a tail on the coin toss. Are the events A and C mutually exclusive?

Answers

Answer:

Step-by-step explanation:

Given that special deck of cards has 20 cards. Nine are green, seven are blue, and four are red. When a card is picked, the color of it is recorded. An experiment consists of first picking a card and then tossing a coin

A) Sample space will have Green, Head,  or Green, Tail .... Red, head, red, tail

No of elements in sample space = no of colours x no of outcomes in coin toss

= 4x2 = 8

B) A= getting (RT)

P(A) = Prob of getting red card and tail on coin

= P (R) *P(T)

=[tex]\frac{4}{20} *\frac{1}{2} \\=\frac{1}{10}[/tex]

C) B be the event that a green or blue is picked, followed by landing a tail on the coin toss

B = getting green card and tail

Getting green card tail is mutally exclusive with red card and tail as there is no common element between green and blue.

D) C= red or green card is picked followed by tail.

Here A and C have a common element as getting red and tail.  So not mutually exclusive

Final answer:

The sample space of the card and coin toss experiment consists of 40 elements. The probability of picking a red card followed by a tail coin toss is 0.1. Events A and B, as well as events A and C, are not mutually exclusive.

Explanation:

Probability in a Card and Coin Toss Experiment

When dealing with a special deck of cards and a subsequent coin toss, multiple steps are involved in determining outcomes and probabilities. As for the given student's question:

A). The sample space contains multiple elements based on the card colors and the side of the coin: each of the 20 cards can result in either heads or tails, creating a total of 40 possible outcomes.

B). For event A, where a red card is picked followed by a tails on the coin toss, the probability (P(A)) is calculated by dividing the number of successful outcomes by the number of total possibilities, resulting in P(A) = 4 (red cards) * 1 (tails outcome) / 40 (total outcomes) = 0.1.

C). Event A and event B are not mutually exclusive because event B involves picking either a green or blue card and also getting tails, which does not overlap with the specifics of event A.

D). Similarly, events A and C are not mutually exclusive. Although both involve picking a red card and landing a tail, event C also includes picking a green card, which does not interfere with the occurrence of event A.

If a distribution has "fat tails," it exhibits A. positive skewness B. negative skewness C. a kurtosis of zero. D. excess kurtosis. E. positive skewness and kurtosis.

Answers

Answer: D. Excess Kurtosis

Step-by-step explanation:

A fat tailed distribution is a kind of probability distribution that exhibits excess kurtosis because it means the resulting numbers from the probability distribution are on a large scale power increment or very small/ slow decreeing order. This makes the graph on the distribution literally fat tailed and makes skewness in such distribution data extremely difficult to ascertain.

Final answer:

Fat tails in a distribution signify excess kurtosis, which signifies more extreme values or outliers than in a normal distribution. Neither positive skewness, negative skewness, nor a kurtosis of zero signify a distribution's 'fat tails'.

Explanation:

If a distribution has 'fat tails', it represents 'excess kurtosis'. This term is used to describe a distribution of data that features tails that are fatter and longer than in a normal distribution. This often means the distribution exhibits more extreme values or outliers. When a distribution has excess kurtosis, it has strong outliers.

Positive skewness, negative skewness, and a kurtosis of zero have no correlation with 'fat tails'. While skewness refers to the asymmetry of a distribution, and a kurtosis of zero refers to a normal distribution, neither of these refer to the concept of 'fat tails'.

So, Fat tails in a distribution signify excess kurtosis, not positive skewness, negative skewness, or a kurtosis of zero.

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What does the term "expand" mean in mathematics?

I am NOT searching for "expanded form" or "distribute".

Answers

I think expanding means to remove the parentheses/brackets from a problem.

For example: Say we have the expression: 3 (4 + 5). I think expanding means to multiply 3, by every number in the parentheses. So that means:

(3 * 4) + (3 * 5) = 27.

Another way to think about it is to (if you're on paper) draw a line from 3, to all the numbers inside the parentheses. The line that connects from 3 to 4, is signaling for you to multiply 3 * 4 = 12. And the line from 3 to 5 = 3 * 5 = 15. And add them.

Final answer:

In mathematics, 'expand' refers to writing an expression in an extended form using distribution. This can result in a polynomial or an infinite series, as seen in binomial expansion or exponential arithmetic.

Explanation:

In mathematics, to expand means to increase the length of an expression by distributing multiplication over addition or subtraction. For example, expanding (a + b)(c + d) results in ac + ad + bc + bd. This does not change the value of the expression, but rather writes it in an alternative form that might be more useful for further operations, such as simplification or evaluation. Binomial expansion, specifically, refers to expressing a binomial raised to a power as a series of terms, using the binomial theorem, which can sometimes result in an infinite series or a polynomial of finite length. This expansion is applicable in situations like expanding (x + y)^n or when dealing with power series expansions of standard mathematical functions including exponential arithmetic where numbers are expressed as a product of a digit term and an exponential term such as in the notation 4.57 x 10^3.

The following probability distributions of jobsatisfaction scores for a sample of informationsystems (IS) senior executives and IS middle managersrange from a low of 1 (very dissatisfied) to a high of5 (very satisfied).Probability Job Satisfaction Score IS SeniorExecutives 1 .05 2 .093 .03 4 .425 .41IS Middle Managers.04.10.12.46.28a. What is the expected value of the job satisfactionscore for senior executives?b. What is the expected value of the job satisfactionscore for middle managers?c. Compute the variance of job satisfaction scores forexecutives and middle managers.d. Compute the standard deviation of job satisfactionscores for both probability distributions.e. Compare the overall job satisfaction of seniorexecutives and middle managers.

Answers

Answer:

a) 4.076

b) 3.9

c) variance for executives=1.128

variance for middle mangers=0.73

d)standard deviation for executives=1.062

standard deviation for middle mangers=0.854

e) Overall job satisfaction for senior executives is higher than middle manager.

Step-by-step explanation:

IS senior executives

Job Satisfaction       1    2          3       4     5

Probability          0.05 0.093 0.03 0.425 0.41

IS middle manager

Job Satisfaction  1       2    3        4    5

Probability         0.01 0.1 0.12 0.46 0.28

Let X denotes IS senior executive and Y denotes IS middle manager.

a)

E(X)=∑x*p(x)=1*0.05+2*0.093+3*0.03+4*0.425+5*0.41

E(X)=0.05+0.186+0.09+1.7+2.05

E(X)=4.076

b)

E(Y)=∑y*p(y)=1*0.1+2*0.1+3*0.12+4*0.46+5*0.28

E(Y)=0.1+0.2+0.36+1.84+1.4

E(Y)=3.9

c)

V(x)=∑x²*p(x)-(∑x*p(x))²

∑x²*p(x)=1*0.05+4*0.093+9*0.03+16*0.425+25*0.41

∑x²*p(x)=0.05+0.372+0.27+6.8+10.25

∑x²*p(x)=17.742

V(x)=17.742-(4.076)²

V(x)=1.128

V(y)=∑y²*p(y)-(∑y*p(y))²

∑y²*p(y)=1*0.1+4*0.1+9*0.12+16*0.46+25*0.28

∑y²*p(y)=0.1+0.4+1.08+7.36+7

∑y²*p(y)=15.94

V(y)=15.94-(3.9)²

V(y)=0.73

d)

S.D(x)=√V(x)

S.D(x)=√1.128

S.D(x)=1.062

S.D(y)=√V(y)

S.D(y)=0.854

e)

Overall job satisfaction for senior executives is more than middle manager as expected value of senior executives is greater than expected value of middle manger with relatively higher variability than middle manager.

Find the probability that the age of a randomly chosen American (a) is less than 20. (b) is between 20 and 49. (c) is greater than 49. (d) is greater than 29

Answers

Answer: i think its B

Step-by-step explanation:

Abby is buying a widescreen TV that she will hang on the wall between two windows. The windows are 36 inches apart, and wide screen TVs are approximately twice as wide as they are tall. Of the following, which is the longest that the diagonal of a widescreen TV can measure and still fit between the windows

Answers

Answer:

D < 40.2 inches

Step-by-step explanation:

The maximum width of the TV must be 36 inches. Since TVs are approximately twice as wide as they are tall, the maximum height is 18 inches.

The diagonal of a TV can be determined as a function of its width (w) and height (h) as follows:

[tex]d^2=h^2+w^2\\d=\sqrt{18^2+36^2}\\d= 40.2\ in[/tex]

Therefore, the diagonal must be at most 40.2 inches.

Since the answer choices were not provided with the question, you should choose the biggest value that is under 40.2 inches.

The maximum diagonal size of the widescreen TV that can fit between two windows 36 inches apart is slightly more than 40 inches, given that the TV has an aspect ratio where the width is about twice the height.

Let's denote the TV's width as w and the height as h. Given that widescreen TVs are about twice as wide as they are tall, we can express the width as w = 2h.

The diagonal d of the TV can be found using Pythagoras' theorem where d² = w² + h².

Substituting 2h for w, we get d² = (2h)² + h² which simplifies to d² = 4h² + h² and further to d² = 5h².

Thus, d = h√5.

If the space between windows is 36 inches, this would be the maximum width of the TV. Therefore, 36 = 2h which means that h = 18 inches. Using this height in the diagonal equation, we get d = 18√5 which is approximately 40.2 inches. This means the longest diagonal of the widescreen TV that can fit between the windows is slightly more than 40 inches.

Suppose a newspaper article states that the distribution of auto insurance premiums for residents of California is approximately normal with a mean of $1,650. The article also states that 25% of California residents pay more than $1,800.

(a) What is the Z-score that corresponds to the top 25% (or the 75th percentile) of the standard normal distribution? (use the closest value from table B.1)

(b) What is the mean insurance cost? $

What is the cut off for the 75th percentile? $

(c) Identify the standard deviation of insurance premiums in LA.

Answers

Final answer:

The Z-score for the 75th percentile is approximately 0.675. The mean insurance cost is $1,650, and the cut off for the 75th percentile is $1,800. The standard deviation of insurance premiums in LA is about $222.22.

Explanation:

(a) The Z-score corresponding to the 75th percentile of the standard normal distribution is approximately 0.675. This is determined referring to standard statistical tables or calculators.

(b) The mean insurance cost is given as $1,650.

The cut off for the 75th percentile is $1,800. This is based on the given information that 25% of California residents pay more than $1,800.

(c) To determine the standard deviation, we first subtract the mean from the 75th percentile value ($1,800 - $1,650 = $150), then divide by the Z-score (150 / 0.675 = approximately $222.22). So, the standard deviation for LA auto insurance premiums is about $222.22.

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Final answer:

The Z-score for the 75th percentile of the standard normal distribution is approximately 0.67. The mean insurance cost is $1,650, and the cutoff for the 75th percentile is $1,800. While we can't identify the standard deviation of insurance premiums in LA without additional data, it would be theoretically possible to find it using the Z-score formula.

Explanation:

In response to your question, let's take it step by step:

(a): The Z-score that corresponds with the 75th percentile of the standard normal distribution is approximately 0.67. You can find this value by utilizing a look-up table (table B.1).

(b): Given in the question, the mean insurance cost for California residents is $1,650.

The 75th percentile (or cutoff) is $1,800, signifying that 25% of residents pay more than this amount.

(c): Unfortunately, the information provided in the question doesn't offer enough data to figure out the standard deviation for insurance premiums in LA directly. However, based on the details given, you can conclude that for a Z-score of 0.67, the corresponding cost is $1,800. Using the Z-score formula, (X - μ) / σ, where X is the value from the dataset, μ is the mean, and σ is the standard deviation, you could theoretically solve for σ (standard deviation) if all other values are known.

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Consider the following function.

f(x) = (4 − x)e−x

(a) Find the intervals of increase or decrease. (Enter your answers using interval notation.)

increasing
decreasing

(b) Find the intervals of concavity. (Enter your answers using interval notation. If an answer does not exist, enter DNE.)

concave up
concave down

(c) Find the point of inflection. (If an answer does not exist, enter DNE.)

(x, y) =

Answers

Answer:

a) decreases at interval (-∞,5) and  increases at (5,∞)

b)  is convave down at interval (-∞,6) an up at interval (6,∞)

c) f(x) has an inflexion point at x=6

Step-by-step explanation:

a) for the function

f(x) = (4 − x)*e^(−x)

then the derivative of f(x) indicates if the function decreases or increases. Thus

f'(x) =df(x)/dx = -e^(−x) -(4 − x)*e^(−x)= (x-5)*e^(−x)

since e^(−x) is always positive , then

f'(x) < 0 for x<5 → f(x) decreases when x<5 ( interval (-∞,5) )

f'(x) > 0 for x>5 → f(x) increases when x>5 ( interval (5,∞) )

f'(x) = 0 for x=5 → f(x) has a local minimum ( since first decreases and then increases)

b) the concavity is found with the second derivative of f(x) , then

f''(x) =d²f(x)/(dx)² = e^(−x) - (x-5)*e^(−x) = (6-x)*e^(−x)

then

f''(x) < 0 for x>6 → f(x) is convave up for x>6 ( interval (6,∞) )

f'(x) > 0 for x<6 → f(x) is concave down  when x<6 ( interval (-∞,6) )

f'(x) = 0 for x=6 → f(x) has an inflection point at x=6

Final answer:

The function f(x) = (4 - x)e^-x is decreasing on the interval (-∞, 1), increasing on (1, ∞), concave up on (2, ∞), concave down on (-∞, 2), and has its point of inflection at [tex](2, 2e^-^2).[/tex]

Explanation:

To find the intervals of increase or decrease, we first need to find the derivative f'(x) of the function f(x) = (4 - x)e-x. Using the product rule and chain rule, we find [tex]f'(x) = e-x - (x - 4)e-x.[/tex]

Setting f'(x) to zero and solving for x, we find the critical points x = 1 and x = 4. Using test points, we determine that the function is decreasing on (-∞, 1) and increasing on (1, ∞).

Next, we find the second derivative [tex]f''(x) = -2e-x + 2(x - 4)e-x[/tex] to determine concavity. Setting f''(x) equal to zero and solving for x, we find x = 2. Using test points, we find that the function is concave up on (2, ∞) and concave down on (-∞, 2). Since the function changes concavity at x = 2, this is the point of inflection.

Substituting x = 2 into the original function f(x), we find y = 2e-2, so the point of inflection is (2, 2e-2).

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the average cost of living in san francisco?

Answers

Step-by-step explanation:

The median rent for a one-bedroom apartment stands at $3,460 a month.

Also The estimated cost of annual necessities for a single person is $43,581 — or $3,632 a month, making it the most expensive city for single people to settle down in.

And For a family of four, expect to pay about $91,785 a year for necessities — that's $7,649 per month.

For a family of four, expect to pay about $91,785 a year for necessities — that's $7,649 per month.

Final answer:

Although exact data isn't provided, information on related costs such as average salary and gasoline prices suggest that the average cost of living in San Francisco is high.

Explanation:

The average cost of living in San Francisco is significantly higher than the national average. According to Numbeo, San Francisco's overall cost of living index is 176.89, which is 76.89% higher than the U.S. average of 100. This means that you can expect to pay about 77% more for goods and services in San Francisco than you would in the average American city.

However, we can infer that the cost of living is high, considering the mean starting salary for San Jose State University graduates, nearby to San Francisco, is at least $100,000 per year. This suggests that a significant income is required to support oneself in the Bay Area.

Other factors indirectly hint at the costs associated with San Francisco living. For instance, the average cost of unleaded gasoline in the Bay Area was once $4.59, which is notably high. These pieces of information, though incomplete, indicate a high cost of living.

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a 50m long chain hangs vertically from a cunlinder attached to a winch. Assume there is no friction in the system and that the chain has a density of 10kg/m. how much work is required to wind the chain into the cylinder if a 50kg block is attached to the end of the chain?

Answers

Answer:

147000 J

Step-by-step explanation:

We are given that

Length of chain=L=50 m

Density of chain=[tex]\rho=10kg/m^3[/tex]

We have to find the work done required to wind the chain into the cylinder if a 50 kg block is attached to the end of the chain.

Work done=[tex]\int_{a}^{b}F(y)dy[/tex]

We have F(y)=[tex]\rho g(50-y)dy[/tex]

a=0 and  b=50

[tex]g=9.8m/s^2[/tex]

Using the formula

Work done=[tex]w_1=10\times 9.8\int_{0}^{50}(50-y)dy[/tex]

Where Length of chain is (50-y) has to be lifted.

Work done=[tex]w_1=10\times 9.8[50y-\frac{y^2}{2}]^{50}_{0}[/tex]

By using the formula [tex]\int x^ndx=\frac{x^{n+1}}{n+1}+C[/tex]

Work done=[tex]w_1=10\times 9.8\times (50(50)-\frac{(50)^2}{2})=98\times (2500-1250)=122500 J[/tex]

When the chain is weightless then the work done required to lift the block attached to the 50 m long chain

Again using the formula

Where f(y)=mg

[tex]w_2=\int_{0}^{50}mgdy[/tex]

We have m=50 kg

[tex]w_2=\int_{0}^{50}50\times 9.8 dy=490[y]^{50}_{0}=490\times 50=24500 J[/tex]

The work done required  to wind the chain into the cylinder if a 50 kg block is attached to the end of the chain=[tex]w_1+w_2=122500+24500=147000 J[/tex]

1) Let f(x)=ax2+bx+c for some value of a, b and c. f intersects the x-axis when x=−2 or x=3, and f( 1 3 )=−25. Find the values of a, b and c and sketch the graph of f(x).
2) A right prism has a base that is an equilateral triangle. The height of the prism is equal to the height of the base. If the volume of the prism is 81, what are the lengths of the sides of the base?
thank u sm

Answers

Answer:

1) a = -⅙, b = ⅙, c = 1

2) 6 units

Step-by-step explanation:

1) f(x) = ax² + bx + c

Given the roots, we can write this as:

f(x) = a (x + 2) (x − 3)

We know that f(13) = -25, so we can plug this in to find a:

-25 = a (13 + 2) (13 − 3)

-25 = 150a

a = -⅙

Therefore, the factored form is:

f(x) = -⅙ (x + 2) (x − 3)

Distributing:

f(x) = -⅙ (x² − x − 6)

f(x) = -⅙ x² + ⅙ x + 1

Graph: desmos.com/calculator/6m6tjoodvb

2) Volume of a right prism is area of the base times the height.

V = Ah

The base is an equilateral triangle.  Area of a triangle is one half the base times height.

V = ½ ab h

The height of the triangle is the same as the height of the prism.

V = ½ bh²

In an equilateral triangle, the height is equal to half the base times the square root of 3.

V = ½ b (½√3 b)²

V = ⅜ b³

Given that V = 81, solve for b.

81 = ⅜ b³

216 = b³

b = 6

According to the National Household Survey on Drug Use and Health, when asked in 2012, 41% of those aged 18 to 24 years used cigarettes in the past year, 9% used smokeless tobacco, 36.3% used illicit drugs, and 10.4% used pain relievers or sedatives. Explain why it is not correct to display these data in a pie chart.

a. The types of illicit drugs are not given.
b. There could be roundoff error.
c. The three groups do not add up to 100%.
d. There have to be more than three categorical variables.
e. There could be overlap between the groups.

Answers

Final answer:

The correct answer is c. The three groups do not add up to 100%. A pie chart is used to display the parts of a whole, where each category represents a proportion of the total. In this case, the categories of cigarette use, smokeless tobacco use, illicit drug use, and pain reliever/sedative use do not add up to 100% when combined. As a result, a pie chart would not accurately represent the data.

Explanation:

The correct answer is c. The three groups do not add up to 100%.

A pie chart is used to display the parts of a whole, where each category represents a proportion of the total. In this case, the categories of cigarette use, smokeless tobacco use, illicit drug use, and pain reliever/sedative use do not add up to 100% when combined. As a result, a pie chart would not accurately represent the data.

The intelligence quotients (IQs) of 16 students from one area of a city showed a mean of 107 and a standard deviation of 10, while the IQs of 14 students from another area of the city showed a mean of 112 and a standard deviation of 8. Is there a significant difference between the IQs of the two groups at significance level of 0.01. What is the alternative hypothesis?

Answers

Answer:

No, there is no significant difference between the IQs of the two groups.Alternative Hypothesis is that the two groups have different IQs os students.

Step-by-step explanation:

We are provided that IQs of 16 students from one area of a city had a mean of 107 and a standard deviation of 10 while the IQs of 14 students from another area of the city had a mean of 112 and a standard deviation of 8.

And we have to check that is there a significant difference between the IQs of the two groups.

Firstly let,    Null Hypothesis, [tex]H_0[/tex] : The two groups have same IQs { [tex]\mu_1 = \mu_2[/tex] }

          Alternate Hypothesis, [tex]H_1[/tex] : The two groups have different IQs{ [tex]\mu_1 \neq \mu_2[/tex]}

Since we don't know about population standard deviations;

The test statistics we will use here will be ;

            [tex]\frac{(X_1bar - X_2bar)- (\mu_1 - \mu_2) }{s_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2} } }[/tex] follows t distribution with [tex](n_1 + n_2 -2)[/tex] degree

                                                    of freedom { [tex]t_n__1 +n_2 - 2[/tex] }

 Here, [tex]X_1bar[/tex] = 107      [tex]X_2bar[/tex] = 112         [tex]s_1[/tex] = 10          [tex]s_2[/tex] = 8

           [tex]n_1[/tex] = 16                [tex]n_2[/tex] = 14

           [tex]s_p[/tex] = [tex]\sqrt{\frac{(n_1 - 1)*s_1^{2} + (n_2 -1)*s_2^{2} }{(n_1 + n_2 -2)} }[/tex] = 9.1261

  Test statistics = [tex]\frac{(107-112) - 0}{9.1261*\sqrt{\frac{1}{16} +\frac{1}{14} } }[/tex]  follows [tex]t_2_8[/tex]

                           = -1.50

Now at 1% level of significance t table is giving the critical value of -2.467 and our test statistics is higher than this means it does not fall in the rejection region so we will accept our null hypothesis and conclude that there is no significant difference between the IQs of the two groups.

Final answer:

This question can be addressed by conducting a two-sample t-test to determine if there is a significant difference between the mean intelligence quotients of students from two areas of a city. The steps include calculating pooled standard deviation, followed by standard error, calculating the t-score, and comparing it to a critical value. You can either reject or fail to reject the null hypothesis based on these results.

Explanation:

The question is asking if there is a significant difference in the mean intelligence quotients (IQs) of students between two areas of a city. Conducting a two-sample t-test can address this. First, let's define the null and alternative hypotheses.

Null Hypothesis (H₀): There is no significant difference between the two sets of IQ scores (mean1 = mean2).Alternative Hypothesis (Hᵃ): There is a significant difference between the two sets of IQ scores (mean1 ≠ mean2).

To perform this test, follow these steps:

Calculate the pooled standard deviation for the two samples.Use it to determine the standard error of the difference between the two means.Use these to calculate the t-score.Compare the t-score with the critical value for the t-distribution with a significance level of 0.01. If the t-score exceeds the critical value, you reject the null hypothesis, i.e., there's a significant difference in IQs between the areas of the city. While if it is less, the null hypothesis is not rejected, thus, no significant difference.

Remember, depending on the specific results, we may or may not find enough evidence to support the alternative hypothesis.

Learn more about Two-sample t-test here:

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I need help please!!!!

Answers

Answer:

x = 14.48

Step-by-step explanation:

first we have to see that we have the measurements from all sides

and we know that the angle between side 21 and 20 is 90 degrees

well to start we have to know the relationships between angles, legs and the hypotenuse.

a: adjacent

o: opposite

h: hypotenuse

sin α = o/h

cos α= a/h

tan α = o/a

let's take the left angle as α

sin α = 21/29

α = sin^-1 (21/29)

α = sin^-1 (0.7241)  

α = 46.397

Now we do the same with the smaller triangle

tan α = o/a

sin 46.397  = x/20

0.724 = x/20

0.724 * 20 = x

14.48 = x

x = 14.48

if we want to check it we can do the same procedure with the other angle

Calculate descriptive statistics for the variable (Coin) where each of the thirty-five students in the sample flipped a coin 10 times. Round your answers to three decimal places and write the mean and the standard deviation.

Answers

Answer:

Mean = 5; Standard Deviation: 1.5811

Step-by-step explanation:

Given Data:

number of times coin flipped = n = 10;

probability of each side of coin = p = 0.5;

Here mean is the product of number of times coin flipped and probability of each

m = n*p =10*0.5 = 5

Standard deviation is obtained by taking square root of product of n,p,q

St. Dev= [tex]\sqrt{npq}[/tex] = [tex]\sqrt{10*0.5*0.5}[/tex] = 1.5811

We have:

           Mean = 5         ;          Standard Deviation = 1.5811

For each gym class a school has 10 soccer balls and 6 volleyballs all of the classes share 15 basketballs. The expression 10c+6c+15 represents the total number of balls the school has for c classes what is a simpler form of the expression

Answers

Answer:

[tex]16c+15[/tex]

Step-by-step explanation:

we have the expression

[tex]10c+6c+15[/tex]

step 1

We can simplify the expression by combining like terms. That is, the terms with the same variable

[tex](10c+6c)+15[/tex]

[tex]16c+15[/tex]

Answer: 16c+15

Step-by-step explanation:

Step 1

Write down the given expression (10c+6c)+15

Step 2

10+6 = 16c

So, 16c+15

Hope this helps! (✿◡‿◡)

A study is designed to test the effect of light level on exam performance of students. The researcher believes that light levels might have different effects on males and females, so wants to make sure both arc equally represented in each treatment. The treatments are fluorescent overhead lighting, yellow overhead lighting, no overhead lighting (only desk lamps).

(a) What is the response variable?
(b) What is the explanatory variable? What arc its levels?
(c) What is the blocking variable? What arc its levels?

Answers

Final answer:

In the given study the response variable is the exam performance, the explanatory variable is the light level, and the blocking variable is the gender of the students.

Explanation:

In this study, the response variable is the exam performance of the students. This is what is being measured as an outcome. The explanatory variable is the light level. The different light levels (fluorescent overhead lighting, yellow overhead lighting, or no overhead light and only desk lamps) constitute the treatments are its levels. The blocking variable in this case is the gender of the students. By making sure that both males and females are equally represented in each treatment, the researcher is controlling for the effect of gender. The levels of this blocking variable are male and female.

Learn more about Experimental Design here:

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The study measures the effect of light level (explanatory variable) on student exam performance (response variable), with gender as a blocking variable. Lurking variables and study design elements like random assignment and blinding are crucial for maintaining the validity of the results.

a) In the study described, the response variable is the exam performance of the students. This variable will be measured to assess the impact of different lighting conditions on students' ability to perform on an exam.

b) The explanatory variable, or independent variable, is the type of lighting. The levels of this variable are fluorescent overhead lighting, yellow overhead lighting, and no overhead lighting (only desk lamps).

c) The blocking variable is gender. The researcher wants to make sure that both males and females are equally represented in each treatment to test the hypothesis that light levels might affect genders differently. The levels of this variable are simply male and female.

When selecting participants, it is important to consider random assignment to ensure that each treatment group is similar in all respects other than the treatment itself. The idea of dividing participants to drive without distraction and to text and drive could be problematic due to ethical considerations and the introduction of confounding variables.

Lurking variables that could interfere with the study on light levels might include the time of day the exam is taken, students' prior knowledge and preparation levels, or even the difficulty of the exam itself.

Blinding could be used by ensuring that the person measuring exam performance does not know which lighting condition the student was exposed to, thus preventing any bias in the evaluation of the exam performance.

Waiting in line. A quality - control manager at an amusement park feels that the amount of time that people spend waiting in line for the American Eagle roller coaster is too long. To determinate if a new loading/unloading procedure if efective in reducing wait time in line, he measured the amount of time (in minutes) people are waiting in line for 7 days. After implementing the new procedure, he again measures the amount of time in minutes and people are waiting in line 7 days and obtains the following data.

Wait time before new procedure
Day
Mon Tues Wed Thurs Fri Sat Sat Sun Sun
11.6 25.9 20.0 38.2 57.3 32.1 81.8 57.1 62.8

Wait time after new procedure
10.7 28.3 19.2 35.9 59.2 31.8 75.3 54.9 62.0

test the claim that the new loading/unloading procedure is effective in reducing wait time (H0: µd=0 and H1: µd<0)at α=.05 level of significance. Note: A normal probability plot and boxplot of the data indicate that the differences are approximately normally distributed with no outliers (use the classical approach and the p-value approach).

Answers

Answer:

No

explanation:

given:

n=9

[tex]\alpha[/tex]=0.05

see the attachment

Determine the sample mean of the differences. The mean is the sum of all values divided by the number of values.

d=0.9-2.4+0.8+...+6.5+2.2+0.8/9

 =1.0556

The variance is the sum of squared deviations from the mean divided by n-1. The standard deviation is the square root of the variance. Determine the sample standard deviation of the differences:  

s_d=√(0.9-1.0556)^2+...+(0.8-1.0556)^2/9-1

     =2.6

CLASSICAL APPROACH :

Given claim: new procedure reduces [tex]u_{d}[/tex] > 0  

The claim is either the null hypothesis or the alternative hypothesis The null hypothesis and the alternative hypothesis state the opposite of each other The null hypothesis needs to contain an equality  

[tex]H_{0}:u_{d}=0\\ H_{1}:u_{d}>0[/tex]

Determine the value of the test statistic

t=d-[tex]u_{d}[/tex]/s_d/√n

=1.220

Determine the critical value from the Student T distribution table in the appendix in the row with d_f = n- 1 = 9-1 = 8 and in the column with [tex]\alpha[/tex] = 0.05  t =1.860  

The rejection region then contains all values larger than 1.860  

If the value of the test statistic is within the failed region, then the null hypothesis is failed

1.220 < 1.860 failed H_0

There is not sufficient evidence to support the claim that the new loading/unloading procedure is effective in reducing the wait time.  

P VALUE APPROACH:

Given claim: new procedure reduces [tex]u_{d}[/tex]  > 0  

The claim is either the null hypothesis or the alternative hypothesis. The null hypothesis and the alternative hypothesis state the opposite of each other. The null hypothesis needs to contain an equality.  

[tex]H_{0}:u_{d}=0\\ H_{1}:u_{d}>0[/tex]

Determine the value of the test statistic:  

 t=d-[tex]u_{d}[/tex]/s_d/√n

The P-value is the probability of obtaining the value of the test statistic, or a value more extreme, assuming that the null hypothesis is true. The P-value is the number (or interval) in the column title of the Students T distribution in the appendix containing the t-value in the row d_f = n-1 = 9-1 = 8

0.10 < P < 0.15

If the P-value is less than the significance level, reject the null hypothesis.  

P > 0.05   failed H_0

There is not sufficient evidence to support the claim that the new loading unloading procedure is effective in reducing the wait time.  

How many pounds of oranges do the data in the plot line represent?

Answers

Answer:

OPTION C: [tex]$ \textbf{37} \frac{\textbf{28}}{\textbf{8}} $[/tex] pounds.

Step-by-step explanation:

From the figure we can see that there are three dots against [tex]$ 3 \frac{7}{8} $[/tex].

That means it becomes [tex]$ 3 \times 3\frac{7}{8} $[/tex].

Note that if there is a mixed fraction of the form [tex]$ a \frac{b}{c} $[/tex]   =   [tex]$ a + \frac{b}{c} $[/tex].

Therefore, [tex]$ 3 \times 3\frac{7}{8} = 3 \times \bigg(3 + \frac{7}{8} \bigg ) $[/tex]                ... (1)

Similarly, against 4 there are 2 dots.

So, it should be [tex]$ 4 \times 2 $[/tex] pounds.                   ...(2)

3 dots against [tex]$ 4 \frac{1}{8} $[/tex].

So, it becomes [tex]$ 3 \times \bigg(4 + \frac{1}{8} \bigg) $[/tex]                       ...(3)

Similarly, 2 dots against [tex]$ 4 + \frac{2}{8} $[/tex].

This will become [tex]$ 2 \times \bigg( 2 + \frac{2}{8} \bigg) $[/tex]                  ...(4)

Now, to calculate the total pound, we simply add (1), (2), (3) & (4).

⇒    [tex]$ 3 \times \bigg(3 + \frac{7}{8} \bigg ) $[/tex]     [tex]$ + $[/tex]      [tex]$ 4 \times 2 $[/tex]       +     [tex]$ 3 \times \bigg(4 + \frac{1}{8} \bigg) $[/tex]       [tex]$ + $[/tex]        [tex]$ 2 \times \bigg( 2 + \frac{2}{8} \bigg) $[/tex]

⇒    [tex]$ 9 + \frac{21}{8} + 8 + 12 + \frac{3}{8} + 8 + \frac{4}{8} $[/tex]

⇒    [tex]$ \bigg ( 9 + 8 + 12 + 8 \bigg) + \bigg( \frac{21 + 3 + 4}{8} \bigg ) $[/tex]

⇒ [tex]$ \textbf{37} \textbf {+} \frac{\textbf{28}}{\textbf{8}} $[/tex]  [tex]$ \textbf{=} \hspace{1mm} \textbf{37} \frac{\textbf{28}}{\textbf{8}} $[/tex] which is the required answer.

. During a year, the probability a structure will be damaged by an earthquake (A) is 0.02, that it will be damaged by a hurricane (B) is 0.03, and that it will be damaged by both is 0.007. What is the probability that it will not be damaged by a hurricane or an earthquake during that year?

Answers

Answer:

0.9506

Step-by-step explanation:

Pr(A) = 0.02

Pr(B) = 0.03

Pr(both) = 0.007

So,

Pr(Not A) = 1 - Pr(A)

               = 1 - 0.02

               = 0.98

Pr(Not B) = 1 - Pr(B)

               = 1 - 0.03

                = 0.97

Pr(Not by both) = 1 - Pr(both)

                          = 1 - 0.007

                          = 0.993

Thus,

Pr(Not B) or Pr(Not A) = 0.97 × 0.98

                                    = 0.9056

∴ the probability that the house would not be damaged by a hurricane or an earthquake during the year is 0.9506.

what is the value of 7 to the 4th power

Answers

Answer:

The value is 2401

Step-by-step explanation:

First we need to understand what's means 7 to the 4th power, or 7^4.

7 is the power base, the power base is the number that we are going to repeat the number of times the exponent says.

4 is the exponent, which will tell us how many times to multiply 7.

So , then we would have

1)                7 x 7 x 7 x 7

2)                  49 x 7 x 7

3)                     343 x 7

4)      finally       2401

How does hypothesis testing differ from constructing confidence intervals, in general? Read carefully.

Answers

Answer:

Step-by-step explanation:

Hypothesis testing invariably used to test a claim about a population parameter is widely used to check whether they hypothetical claim made is right.

For example, mean scores of a particular college is more than 75% is tested with hypothesis as setting null as equal to 75% and alternate >75%

Processes are done stepwise from the sample collected and conclusion made

Confidence interval on the other hand is the range of values within which the parameter is expected to lie at a certain confidence level

Estimated population parameter is provided for error known as margin of error depending upon the confidence level, and an interval is prepared which guarantees to the extent of confidence that parameters will fall within.

Hypothesis testing can be concluded with the use of confidence intervals also.

Write down the general zeroth order linear ordinary differential equation. Write down the general solution.

Answers

The zeroth derivative of a function [tex]y(x)[/tex] is simply the function itself, so the zeroth order linear ODE takes the general form

[tex]y(x)=f(x)[/tex]

whose solution is [tex]f(x)[/tex].

dentify the type of data​ (qualitative/quantitative) and the level of measurement for the native language of survey respondents. Explain your choice. Native language Number of respondents English 759 Spanish 775 French 22 Are the data qualitative or​ quantitative? A. ​Quantitative, because descriptive terms are used to measure or classify the data. B. ​Qualitative, because descriptive terms are used to measure or classify the data. C. ​Qualitative, because numerical​ values, found by either measuring or​ counting, are used to describe the data. D. ​Quantitative, because numerical​ values, found by either measuring or​ counting, are used to describe the data.

Answers

Answer:

The correct option is D i.e. Quantitative because numerical values found by either measuring or counting are used to describe the data.

Step-by-step explanation:

As the number of respondents is a numerical value and is identified by counting thus it is a quantitative variable. Also all the other options are incorrect.

A is incorrect because the reason described is not the property of  quantitative data.

B is incorrect because the data is not described in descriptive terms.

C is incorrect because the reason described in not a property of qualitative data.

Based on a Pitney Bowes survey, assume that 42% of consumers are comfortable having drones deliver their purchases. Suppose we want to find the probability that when five consumers are randomly selected, exactly two of them are comfortable with the drones. What is wrong with using the multiplication rule to find the probability of getting two consumers comfortable with drones followed by three consumers not comfortable, as in this calculation: 10.42210.42210.58210.58210.582 = 0.0344?

Answers

Answer:

For this case is wrong use the multiplication for P(X=2):

0.42*0.42*0.58*0.58*0.58 = 0.0344

Because we don't take in count the possible nCx ways in order to have the two consumers comfortable, and we are assuming that the first two people are comfortable and the rest is not, and that's not the only possibility. The correct probability for X=2 people comfortable is given by:

[tex]P(X=2)=(5C2)(0.42)^2 (1-0.42)^{5-2}=0.344[/tex]

And as we can see the real answer is 10 times the assumed answer, for this reason is wrong the claim.

Step-by-step explanation:

Previous concepts

The binomial distribution is a "DISCRETE probability distribution that summarizes the probability that a value will take one of two independent values under a given set of parameters. The assumptions for the binomial distribution are that there is only one outcome for each trial, each trial has the same probability of success, and each trial is mutually exclusive, or independent of each other".

Solution to the problem

Let X the random variable of interest, on this case we now that:

[tex]X \sim Binom(n=5, p=0.42)[/tex]

The probability mass function for the Binomial distribution is given as:

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

Where (nCx) means combinatory and it's given by this formula:

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

For this case is wrong use the multiplication for P(X=2):

0.42*0.42*0.58*0.58*0.58 = 0.0344

Because we don't take in count the possible nCx ways in order to have the two consumers comfortable, and we are assuming that the first two people are comfortable and the rest is not, and that's not the only possibility. The correct probability for X=2 people comfortable is given by:

[tex]P(X=2)=(5C2)(0.42)^2 (1-0.42)^{5-2}=0.344[/tex]

And as we can see the real answer is 10 times the assumed answer, for this reason is wrong the claim.

Calculate the sample standard deviation and sample variance for the following frequency distribution of heart rates for a sample of American adults. If necessary. round to one more decimal place than the largest number of decimal places given in the data. Heart Rates in Beats per Minute Class Frequency 61-6613 67-72 10 73-78 3 79-8411 85-90 3

Answers

Answer:

[tex] \bar X = \frac{\sum_{i=1}^5 x_i f_i}{n} = \frac{2906}{40}= 72.65[/tex]

[tex] s^2 = \frac{213856 -\frac{2906}{40}}{40-1}=70.131[/tex]

[tex] s = \sqrt{70.131}= 8.374[/tex]

Step-by-step explanation:

For this case we can calculate the expected value with the following table"

Class    Midpoint(xi)   Freq. (fi)       xi fi          xi^2 * fi

61-66     63.5                13             825.5      52419.5  

67-72     69.5               10              695        48302.5

73-78     75.5                3              226.5      17100.75

79-84     81.5                11              896.5      73064.75

85-90    87.5                3              262.5       22968.75

________________________________________________

Total                            40            2906          213856

For this case the midpoint is calculated as the average between the minimum and maximum point for each class.  

The expected value can be calculated with the following formula:

[tex] \bar X = \frac{\sum_{i=1}^5 x_i f_i}{n} = \frac{2906}{40}= 72.65[/tex]

For this case n =40 represent the total number of obervations given,  

And for the sample variance we can use the following formula:

[tex] s^2 = \frac{\sum x^2_i f_i -\frac{\sum x_i f_i}{n}}{n-1}[/tex]

And if we replace we got:

[tex] s^2 = \frac{213856 -\frac{2906}{40}}{40-1}=70.131[/tex]

And for the deviation we take the square root:

[tex] s = \sqrt{70.131}= 8.374[/tex]

Final answer:

To calculate the sample standard deviation and sample variance, first calculate the sample mean, then calculate the sample variance, and finally find the square root of the sample variance to get the sample standard deviation.

Explanation:

To calculate the sample standard deviation and sample variance for the given frequency distribution of heart rates, we need to follow these steps:

Create a chart to organize the data, frequencies, relative frequencies, and cumulative relative frequencies. Calculate the sample mean (average) by multiplying each heart rate value by its frequency, summing those products, and dividing by the total number of observations. Calculate the sample variance by finding the squared difference between each heart rate value and the mean, multiplying each squared difference by its frequency, summing those products, and dividing by the total number of observations minus 1. Calculate the sample standard deviation by taking the square root of the sample variance.

Using the provided data, the sample standard deviation and sample variance can be calculated as follows:

Sample mean = (65 * 13 + 69.5 * 10 + 75.5 * 3 + 81.5 * 11 + 87.5 * 3) / (13 + 10 + 3 + 11 + 3) ≈ 72.74

Sample variance = [(65 - 72.74)² * 13 + (69.5 - 72.74)² * 10 + (75.5 - 72.74)² * 3 + (81.5 - 72.74)² * 11 + (87.5 - 72.74)² * 3] / (13 + 10 + 3 + 11 + 3 - 1) ≈ 54.21

Sample standard deviation = √(54.21) ≈ 7.36

Other Questions
The ____________ method of identifying social class views social class as a statistical category. Select one: a. objective b. self-placement c. reputational d. distributional What were the goals of Mao's "Great Leap Forward"?A He wanted the Chinese to move from rural to urban areasB He wanted the Chinese athletes to excel into the OlympicsC He wanted the Chinese to produce great works of artD He wanted to make China a great industrial power The box plot shows information about the marks scored in a test. Nobody gained 30, 48 or 70 marks. 120 students gained less than 70 marks. How many students gained more than 48 marks? Which description best explains the role of DNA in the differentiation of the cells within an organism? Fill in the blank with the correct verb in the imperfect tense.De nios, mi hermano y yomuy traviesos. (ser)fuimosramossomosseramos Amanda is very mindful to guard what she says to her boyfriend when she is angry so that she won't say something that she will later regret. This best demonstrates the communication principle that says Read the excerpt from a statement issued by President Franklin D. Roosevelt just before signing the Social Security Act into law and answer the question."This law, too, represents a cornerstone in a structure which is being built but is by no means complete. It is a structure intended to lessen the force of possible future depressions. It will act as a protection to future administrations against the necessity of going deeply into debt to furnish relief to the needy. The law will flatten out the peaks and valleys of deflation and of inflation. It is, in short, a law that will take care of human needs and at the same time provide for the United States an economic structure of vastly greater soundness."What issue was the law intended to address? How?Group of answer choicesRoosevelt believed that by exploiting the nation's natural resources, the United States could reestablish itself as a major player in the global economy and enjoy strong economic growth for generations.Roosevelt believed that by empowering the government to create programs to support vulnerable portions of the population, the people and the economy would be better equipped to withstand economic downturns.Roosevelt believed that by eliminating barriers to international trade, the US economy, as well as the global economy, would never again experience a sustained period of economic stagnation and job loss.Roosevelt believed that by creating jobs through public works projects, the government could provide employment for the majority of the American population and prevent another economic depression. Because the researcher had access to twenty years of data on the same participants in an education program, the researcher was able to perform a(n) _________ study. calculate the length of the circumference of a circle with a radius of 3cm List the next four multiples of the unit fraction 1/2 4th grade Does an unbounded feasible region imply that the optimal solution to the linear program will be unbounded? Which of the following techniques is used sparingly because there is a slight but genuine risk of miscarriage or damage to the fetus while having a 99% accuracy in diagnosing genetic problems? amniocentesis CT scan ultrasound chorionic villus sampling (-6,5) and (4,-1) equation For which pairs of functions is (fg)(x)=x of functions is (fg)(x)=x The core idea that both Franklin Roosevelts New Deal and policies from the Progressive Era shared was A. the government has a responsibility to regulate the banking industryB. the government should encourage unions and discourage business cultureC. the government should give aid directly to citizens instead of funding charities D. the government has a responsibility to protect the well-being of its citizens If Whole Foods Market leaders were to engage in a SWOT analysis, they might study which of the following factors as part of the organization's external environment? a. Demographic and population changes within society b. The organizational culture c. Leadership strength and strong succession plans d. The talent pipeline Read the excerpt from Outcasts United. Luma ordered him to stand in goal. She took off her shoes as the boy waited beneath the crossbar, rocking back and forth and growing more anxious by the moment. She asked for a ball, which she placed on the grass. Then, barefoot, as the team looked on, she blasted a shot directly at the boy, who dove out of the way as the ball rocketed into the net. Luma turned toward her team. "Anybody else?" she asked. Take a look at this chart of Lumas actions listed in chronological order. Which sentence best fills in the blank? She asks for the ball. She hears the boy talking about her. She shows off her ball skills. She rocks back and forth. Una es diferenteMultiple choice Activity InstructionsSelect the word that doesn't belong in each group. February 27 11:59 PM 2 attempts remaining Grade settings External referencesVocabulary list 404-407 Questions Modelo mudarse, alquilar, vivienda, alfombra, apartamento 1. sala plato copa vaso taza 2. cuchillo altillo plato copa tenedor 3. cocina balcn patio jardn garaje 4. cartel estante pintura lavadora cuadro 5. dormitorio sala comedor cafetera oficina Earth's atmosphere is constantly bombarded by cosmic ray protons that originate somewhere in space. If the protons all passed through the atmosphere, assume that each square meter of Earth's surface would intercept protons at the average rate of 1110 protons per second. What would be the electric current intercepted by the total surface area of the planet? 3.14 LAB: Input and formatted output: Caffeine levels A half-life is the amount of time it takes for a substance or entity to fall to half its original value. Caffeine has a half-life of about 6 hours in humans. Given caffeine amount (in mg) as input, output the caffeine level after 6, 12, and 24 hours. Use a string formatting expression with conversion specifiers to output the caffeine amount as floating-point numbers.