Question 1

Find the test statistic  for a sample with n = 20,  = 12.7, s = 2.0, and  if  Round your answer to three decimal places.

Accepted Answer

A)  -0.872 
B)  -1.265 
C)  -0.894 
D)  -1.233

Question 2

Determine the critical value,  , to test the claim about the population proportion p ? 0.132 given  and  Use

Accepted Answer

A)  -2.33 
B)  -1.96 
C)  -2.575 
D)  -1.645

Question 3

A local tennis pro-shop strings tennis rackets at the tension (pounds per square inch) requested by the customer. Recently a customer made a claim that the pro-shop consistently strings rackets at lower tensions, on average, than requested. To support this claim, the customer asked the pro shop to string 7 new rackets at 56 psi. Suppose the two-tailed P-value for the test described above (obtained from a computer printout) is  Give the proper conclusion for the test. Use

Accepted Answer

A)  There is sufficient evidence to conclude that ?, the true mean tension of the rackets, is less than 56 psi. 
B)  Reject  and conclude that ?, the true mean tension of the rackets, equals 56 psi. 
C)  Accept  and conclude that ?, the true mean tension of the rackets, equals 56 psi. 
D)  There is insufficient evidence to conclude that ?, the true mean tension of the rackets, is less than 56 psi.

Question 4

A candidate for state representative of a certain state claims to be favored by at least half of the voters. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

Accepted Answer

A)  There is not sufficient evidence to support the claim p ? 0.5. 
B)  There is sufficient evidence to reject the claim p ? 0.5. 
C)  There is sufficient evidence to support the claim p ? 0.5. 
D)  There is not sufficient evidence to reject the claim p ? 0.5.

Question 5

Use a t-test to test the claim μ > 35 at α = 0.005, given the sample statistics n = 25,  = 36, and  Round the test statistic to the nearest thousandth.

Accepted Answer

The answer of Use a t-test to test the claim...

Question 6

Find the test statistic  for a sample with n = 10,  = 15.3, s = 1.3, and  if  Round your answer to three decimal places.

Accepted Answer

A)  -3.186 
B)  -2.617 
C)  -3.010 
D)  -2.189

Question 7

Find the test statistic  for a sample with n = 25,  = 40, s = 3, and ? = 0.005 if  Round your answer to three decimal places.

Accepted Answer

A)  1.997 
B)  1.239 
C)  1.452 
D)  1.667

Question 8

A candidate for state representative of a certain state claims to be favored by at least half of the voters. If a hypothesis test is performed, how should you interpret a decision that fails to reject the null hypothesis?

Accepted Answer

A)  There is sufficient evidence to support the claim p ? 0.5. 
B)  There is sufficient evidence to reject the claim p ? 0.5. 
C)  There is not sufficient evidence to support the claim p ? 0.5. 
D)  There is not sufficient evidence to reject the claim p ? 0.5.

Question 9

The dean of a major university claims that the mean number of hours students study at her University (per day) is at most 5.8 hours. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

Accepted Answer

A)  There is sufficient evidence to reject the claim ? ? 5.8. 
B)  There is not sufficient evidence to support the claim ? ? 5.8. 
C)  There is not sufficient evidence to reject the claim ? ? 5.8. 
D)  There is sufficient evidence to support the claim ? ? 5.8.

Question 10

A local eat-in pizza restaurant wants to investigate the possibility of starting to deliver pizzas. The owner of the store has determined that home delivery will be successful if the average time spent on the deliveries does not exceed 40 minutes. The owner has randomly selected 24 customers and has delivered pizzas to their homes in order to test if the mean delivery time actually exceeds 40 minutes. Suppose the P-value for the test was found to be 0.0 289. State the correct conclusion.

Accepted Answer

A)  At ? = 0.025, we fail to reject  
B)  At ? = 0.05, we fail to reject  
C)  At ? = 0.03, we fail to reject  
D)  At ? = 0.02, we reject

Question 11

The weekly salaries (in dollars) of randomly selected employees of a company are summarized in the boxplot below. Based on the boxplot, is a large sample necessary to conduct a hypothesis test about the mean salary? If so, why?

Accepted Answer

A)  Yes; data do not appear to be normally distributed but skewed left. 
B)  Yes; data do not appear to be normally distributed but skewed right. 
C)  No; data appear to be normally distributed. 
D)  Yes; data contain outliers.

Question 12

Find the test statistic  for a sample with n = 12,  = 20.8, s = 2.1, and  if  Round your answer to three decimal places.

Accepted Answer

A)  -0.825 
B)  -0.037 
C)  -0.381 
D)  -0.008

Question 13

Use a t-test to test the claim μ ≥ 10.7 at α = 0.05, given the sample statistics n = 10,  , and  Round the test statistic to the nearest thousandth.

Accepted Answer

The answer of Use a t-test to test the claim...

Question 14

A local tennis pro-shop strings tennis rackets at the tension (pounds per square inch) requested by the customer. Recently a customer made a claim that the pro-shop consistently strings rackets at lower tensions, on average, than requested. To support this claim, the customer asked the pro shop to string 20 new rackets at 58 psi. Upon receiving the rackets, the customer measured the tension of each and calculated the following summary statistics:   In order to conduct the test, the customer selected a significance level of  Interpret this value.

Accepted Answer

A)  There is a 1% chance that the sample will be biased. 
B)  The smallest value of ? that you can use and still reject  is 0 .01. 
C)  The probability of making a Type II error is 0. 99. 
D)  The probability of concluding that the true mean is less than 58 psi when in fact it is equal to 58 psi is only .01.

Question 15

Use a t-test to test the claim μ ≤ 5.7 at α = 0.05, given the sample statistics n = 15,  , and  Round the test statistic to the nearest thousandth.

Accepted Answer

The answer of Use a t-test to test the claim...

Question 16

Test the claim about the population proportion p = 0.250 given n = 48 and  = 0.231. Use α = 0.01.

Accepted Answer

The answer of Test the claim about the population proportion...

Exam 10: Hypothesis Tests Regarding a Parameter

Find the test statistic for a sample with n = 20, = 12.7, s = 2.0, and if Round your answer to three decimal places.

Determine the critical value, , to test the claim about the population proportion p ? 0.132 given and Use

A candidate for state representative of a certain state claims to be favored by at least half of the voters. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

Use a t-test to test the claim μ > 35 at α = 0.005, given the sample statistics n = 25, = 36, and Round the test statistic to the nearest thousandth.

Find the test statistic for a sample with n = 10, = 15.3, s = 1.3, and if Round your answer to three decimal places.

Find the test statistic for a sample with n = 25, = 40, s = 3, and ? = 0.005 if Round your answer to three decimal places.

A candidate for state representative of a certain state claims to be favored by at least half of the voters. If a hypothesis test is performed, how should you interpret a decision that fails to reject the null hypothesis?

The dean of a major university claims that the mean number of hours students study at her University (per day) is at most 5.8 hours. If a hypothesis test is performed, how should you interpret a decision that rejects the null hypothesis?

The weekly salaries (in dollars) of randomly selected employees of a company are summarized in the boxplot below. Based on the boxplot, is a large sample necessary to conduct a hypothesis test about the mean salary? If so, why?

Find the test statistic for a sample with n = 12, = 20.8, s = 2.1, and if Round your answer to three decimal places.

Use a t-test to test the claim μ ≥ 10.7 at α = 0.05, given the sample statistics n = 10, , and Round the test statistic to the nearest thousandth.

Use a t-test to test the claim μ ≤ 5.7 at α = 0.05, given the sample statistics n = 15, , and Round the test statistic to the nearest thousandth.

Test the claim about the population proportion p = 0.250 given n = 48 and = 0.231. Use α = 0.01.