A recent survey showed that among 700 randomly selected subjects who completed 4 years of college, 151 smoke and 549 do not smoke. Determine a 95% confidence interval for the true proportion of the given population that smokes. 95% CI: to

Total plasma volume is important in determining the required plasma component in blood replacement therapy for a person undergoing surgery. Plasma volume is influenced by the overall health and physical activity of an individual. Suppose that a random sample of 46 male firefighters are tested and that they have a plasma volume sample mean of x = 37.5 ml/kg (milliliters plasma per kilogram body weight). Assume that σ = 7.00 ml/kg for the distribution of blood plasma.

(a) Find a 95% confidence interval for the population mean blood plasma volume in male firefighters. What is the margin of error? (Use 2 decimal places.)

(d) Find the sample size necessary for a 95% confidence level with maximal/marginal error of estimate E = 2.80 for the mean plasma volume in male firefighters.

You wish to test the claim that mu equals880 at a level of significance of alpha equals0.01 and are given sample statistics n equals 35 and x overbar equals 850. Assume the population standard deviation is 82. Compute the value of the standardized test statistic. Round your answer to two decimal places. You wish to test the claim that mu equals880 at a level of significance of alpha equals0.01 and are given sample statistics n equals 35 and x overbar equals 850. Assume the population standard deviation is 82. Compute the value of the standardized test statistic. Round your answer to two decimal places.

A company has 2 types of machines that produce the same product, one recently new and another older. Based on past data, the older machine produces 12% defective products while the newer machine produces 8% defective products. Due to capacity needs, the company must use both machines to meet demand. In addition, the newer machine produces 3 times as many products as the older machine.  

1. Setup a probability table depicting the machine type and defective outcome
2. Given a randomly selected product was tested and found to be defective, what is the probability it was produced by the new machine?
3. What is the probability that any selected product is defective (regardless of machine type)?
4. What is the probability that any selected product is non-defective and produced by the older machine?     

Math & Music (Raw Data, Software Required):
There is a lot of interest in the relationship between studying music and studying math. We will look at some sample data that investigates this relationship. Below are the Math SAT scores from 8 students who studied music through high school and 11 students who did not. Test the claim that students who study music in high school have a higher average Math SAT score than those who do not. Test this claim at the 0.05 significance level.

You should be able copy and paste the data directly into your software program.

(a) The claim is that the difference in population means is positive (μ₁ − μ₂ > 0). What type of test is this?

This is a two-tailed test.

This is a right-tailed test.    

This is a left-tailed test.

(b) Use software to calculate the test statistic. Do not 'pool' the variance. This means you do not assume equal variances.
Round your answer to 2 decimal places.

t = ?

(c) Use software to get the P-value of the test statistic. Round to 4 decimal places.
P-value = ?

(d) What is the conclusion regarding the null hypothesis?

reject H₀

fail to reject H₀    

(e) Choose the appropriate concluding statement.

The data supports the claim that students who study music in high school have a higher average Math SAT score than those who do not.

There is not enough data to support the claim that students who study music in high school have a higher average Math SAT score than those who do not.    

We reject the claim that students who study music in high school have a higher average Math SAT score than those who do not.

We have proven that students who study music in high school have a higher average Math SAT score than those who do not.

The sampled population is normally distributed, with the given information. (Give your answers correct to two decimal places.)

n = 11, x = 29.6, and σ = 6.4

(a) Find the 0.99 confidence interval for μ.
to  

QUESTION 12

1. A teacher would like to estimate the mean grade for her class of 50 students on the most recent exam. After the first 10 tests are graded (in random order), her sample results are as follows:

   45 60 74 75 79 80 85 86 90 96

   Which of the numbers below represent the point estimate?

   	A.	15.4
   	B.	77.0
   	C.	84.0
   	D.	79.5

4. Let N be a Poisson(λ) random variable. We observe N, say it equals n, we then throw a p-biased coin n times and let X be the number of heads we get. Show that X is a Poisson(pλ) random variable. (You can use the following identity: ∑ ∞ k=0 (y^k)/ k! = e^y .)

A reporter estimates that professional golfers have an average height of 70.1 inches, with a variance of 7.17. To test this estimate, a researcher chooses a random sample of 22 professional golfers and finds that their mean height is 70.2 inches, with a variance of 10.40. Do these data provide enough evidence, at the 0.1 level of significance, to reject the claim that the true variance, σ2, of professional golfers' heights is equal to 7.17? Assume that the heights of professional golfers are approximately normally distributed.Perform a two-tailed test. Then fill in the table below. Carry your intermediate computations to at least three decimal places and round your answers as specified in the table.

A random sample of 36 observations is drawn from a population with a mean equal to 51 and a standard deviation equal to 15.

1. What is the mean and the standard deviation of the sampling distribution of x̄?

1. Calculate the z-score corresponding to a value of x̄ = 45.5.
   
   
2. Calculate the z-score corresponding to a value of x̄ = 46.5.
   
   
3. Find P(x̄ ≥ 45.5) (to 4 decimals)
   
   
4. Find P(x̄ < 46.5) (to 4 decimals)
   
   
5. Find P(45.5 ≤ x̄ ≤ 46.5) (to 4 decimals)
   
   
6. There is a 60% chance that the value of x̄ is above  (to 4 decimals).

Assume a 2015 Gallup Poll asked a national random sample of 491 adult women to state their current weight. Assume the mean weight in the sample was ?¯=161.

We will treat these data as an SRS from a normally distributed population with standard deviation ?=36 pounds.

Give a 99% confidence interval for the mean weight of adult women based on these data. Enter the upper and lower values of your confidence interval into the spaces provided rounded to two decimal places.

lower value = pounds

upper value = pounds

Do you trust the interval you computed as a 99% confidence interval for the mean weight of all U.S. adult women? Select an answer choice that correctly explains why or why not.

This interval can be trusted since a 99% confidence interval can be expected to be relatively accurate.

This interval would probably be more trustworthy if the poll contacted women with a wider range of different weights.

This interval can be trusted and seen to be around 99% accurate.

There is probably little reason to trust this interval; it is possible that many of the women either wouldn’t know their current weight or would lie about it.

1.How do we recognize a correctly stated standardized regression equation?

2.After scores have been standardized, the value of the Y intercept will always be what?

3.What does the coefficient of multiple determination show?

4.Under what condition could the coefficient of multiple determination be lower than the zero order correlation coefficients?

5.What is the coefficient of multiple determination with two independent variables?

Retaking the SAT: Many high school students take the SAT's twice; once in their Junior year and once in their Senior year. In a sample of 50 such students, the score on the second try was, on average, 28 points above the first try with a standard deviation of 13 points. Test the claim that retaking the SAT increases the score on average by more than 25 points. Test this claim at the 0.01 significance level.

(a) The claim is that the mean difference is greater than 25 (μ_d > 25), what type of test is this?

This is a two-tailed test.

This is a right-tailed test.    

This is a left-tailed test.

(b) What is the test statistic? Round your answer to 2 decimal places.
t-<sub>d= ?

(c) Use software to get the P-value of the test statistic. Round to 4 decimal places.
P-value = ?

(d) What is the conclusion regarding the null hypothesis?</sub>

reject H₀

fail to reject H₀    

(e) Choose the appropriate concluding statement.

The data supports the claim that retaking the SAT increases the score on average by more than 25 points.

There is not enough data to support the claim that retaking the SAT increases the score on average by more than 25 points.    

We reject the claim that retaking the SAT increases the score on average by more than 25 points.

We have proven that retaking the SAT increases the score on average by more than 25 points.

Suppose x has a distribution with a mean of 80 and a standard deviation of 12. Random samples of size n = 64 are drawn.

(a) Describe the x bar distribution. x bar has an approximately normal distribution. x bar has a Poisson distribution. x bar has a binomial distribution. x bar has an unknown distribution. x bar has a normal distribution. x bar has a geometric distribution. Compute the mean and standard deviation of the distribution. (For each answer, enter a number.) mu sub x bar = mu sub x bar = sigma sub x bar = sigma sub x bar =

(b) Find the z value corresponding to x bar = 83. (Enter an exact number.) z =

(c) Find P(x bar < 83). (Enter a number. Round your answer to four decimal places.) P(x bar < 83) = P(x bar < 83)

(d) Would it be unusual for a random sample of size 64 from the x distribution to have a sample mean less than 83?

Explain.

The Wall Street Journal Corporate Perceptions Study 2011 surveyed readers and asked how each rated the quality of management and the reputation of the company for over 250 worldwide corporations. Both the quality of management and the reputation of the company were rated on an excellent, good, and fair categorical scale. Assume the sample data for 200 respondents below applies to this study.

Use a 0.05 level of significance and test for independence of the quality of management and the reputation of the company.

A) State the null and alternative hypotheses.

H₀: Quality of management is independent of the reputation of the company.
H_a: Quality of management is not independent of the reputation of the company.

H₀: Quality of management is not independent of the reputation of the company.
H_a: Quality of management is independent of the reputation of the company.    

H₀: Quality of management is not independent of the reputation of the company.
H_a: The proportion of companies with excellent management is not equal across companies with differing reputations.

H₀: Quality of management is independent of the reputation of the company.
H_a: The proportion of companies with excellent management is equal across companies with differing reputations.

B) Find the value of the test statistic. (Round your answer to three decimal places.)

C) Find the p-value. (Round your answer to four decimal places.)

D) State your conclusion.

Do not reject H₀. We cannot conclude that the rating for the quality of management is independent of the rating of the reputation of the company.

Reject H₀. We conclude that the rating for the quality of management is not independent of the rating for the reputation of the company.     

Reject H₀. We conclude that the rating for the quality of management is independent of the rating for the reputation of the company.

Do not reject H₀. We cannot conclude that the ratings for the quality of management and the reputation of the company are not independent.

E) If there is a dependence or association between the two ratings, discuss and use probabilities to justify your answer.

For companies with an excellent reputation, the largest column probability corresponds to [ EXCELLENT/GOOD/FAIR ] excellent good fair management quality. For companies with a good reputation, the largest column probability corresponds to [ EXCELLENT/GOOD/FAIR ] excellent good fair management quality. For companies with a fair reputation, the largest column probability corresponds to [ EXCELLENT/GOOD/FAIR ] excellent good fair management quality. Since these highest probabilities correspond to [THE SAME/DIFFERENT ] the same different ratings of quality of management and reputation, the two ratings are [ ASSOCIATED/INDEPENDENT ] associated independent.