I DO NOT NEED STEP BY STEP EXPLANATIONS, JUST THE ANSWERS

Question 11

2pts

A computer manufacturer estimates that its cheapest screens will last less than 2.8 years. A random sample of 61 of these screens has a mean life of 2.5 years. The population is normally distributed with a population standard deviation of 0.88 years. At =0.02, what type of test is this and can you support the organization's claim using the test statistic?

Claim is alternative, fail to reject the null and cannot support claim as test statistic (-2.66) is in the rejection region defined by the critical value (-2.05)

Claim is alternative, reject the null and support claim as test statistic (-2.66) is in the rejection region defined by the critical value (-2.05)

Claim is null, reject the null and support claim as test statistic (-2.66) is in the rejection region defined by the critical value (-2.05)

Claim is null, fail to reject the null and cannot support claim as test statistic (-2.66) is in the rejection region defined by the critical value (-2.05)

Question

12

2pts

A pharmaceutical company claims that the average cold lasts an average of 8.4 days. They are using this as a basis to test new medicines designed to shorten the length of colds. A random sample of 106 people with colds, finds that on average their colds last 8.7 days. The population is normally distributed with a population standard deviation of 0.9 days. At =0.02, what type of test is this and can you support the company's claim using the p-value?

Claim is null, fail to reject the null and support claim as the p-value (0.001) is greater than alpha (0.02)

Claim is alternative, reject the null and support claim as the p-value (0.000) is greater than alpha (0.02)

Claim is alternative, fail to reject the null and cannot support claim as the p-value (0.000) is less than alpha (0.02)

Claim is null, reject the null and cannot support claim as the p-value (0.001) is less than alpha (0.02)

Question

13

2pts

A business receives supplies of copper tubing where the supplier has said that the average length is 26.70 inches so that they will fit into the business' machines. A random sample of 50 copper tubes finds they have an average length of 26.75 inches. The population standard deviation is assumed to be 0.20 inches. At =0.05, should the business reject the supplier's claim?

No, since p>, we fail to reject the null and the null is the claim

No, since p>, we reject the null and the null is the claim

Yes, since p<, we reject the null and the null is the claim

Yes, since p>, we fail to reject the null and the null is the claim

Question

14

2pts

The company's cleaning service states that they spend more than 46 minutes each time the cleaning service is there. The company times the length of 37 randomly selected cleaning visits and finds the average is 47.2 minutes. Assuming a population standard deviation of 5.2 minutes, can the company support the cleaning service's claim at =0.05?

No, since p>, we fail to reject the null. The claim is the alternative, so the claim is not supported

Yes, since p<, we fail to reject the null. The claim is the null, so the claim is not supported

Yes, since p>, we reject the null. The claim is the null, so the claim is not supported

No, since p<, we reject the null. The claim is the alternative, so the claim is supported

Question

15

2pts

A customer service phone line claims that the wait times before a call is answered by a service representative is less than 3.3 minutes. In a random sample of 62 calls, the average wait time before a representative answers is 3.24 minutes. The population standard deviation is assumed to be 0.40 minutes. Can the claim be supported at =0.08?

Yes, since test statistic is in the rejection region defined by the critical value, reject the null. The claim is the alternative, so the claim is supported

No, since test statistic is not in the rejection region defined by the critical value, fail to reject the null. The claim is the alternative, so the claim is not supported

Yes, since test statistic is not in the rejection region defined by the critical value, reject the null. The claim is the alternative, so the claim is supported

No, since test statistic is in the rejection region defined by the critical value, fail to reject the null. The claim is the alternative, so the claim is not supported

Question

16

2pts

In a hypothesis test, the claim is 40 while the sample of 27 has a mean of 41 and a sample standard deviation of 5.9 from a normally distributed data set. In this hypothesis test, would a z test statistic be used or a t test statistic and why?

z test statistic would be used as the population standard deviation is known

t test statistic would be used as the standard deviation is less than 10

z test statistic would be used as the mean is greater than 30

t test statistic would be used as the data are normally distributed with an unknown population standard deviation

Question

17

2pts

A university claims that the mean time professors are in their offices for students is at least 6.5 hours each week. A random sample of twelve professors finds that the mean time in their offices is 6.2 hours each week. With a sample standard deviation of 0.49 hours from a normally distributed data set, can the university's claim be supported at =0.05?

Yes, since the test statistic is in the rejection region defined by the critical value, the null is not rejected. The claim is the null, so is supported

Yes, since the test statistic is not in the rejection region defined by the critical value, the null is not rejected. The claim is the null, so is supported

No, since the test statistic is not in the rejection region defined by the critical value, the null is rejected. The claim is the null, so is not supported

No, since the test statistic is in the rejection region defined by the critical value, the null is rejected. The claim is the null, so is not supported

Question

18

2pts

A credit reporting agency claims that the mean credit card debt in a town is greater than $3500. A random sample of the credit card debt of 20 residents in that town has a mean credit card debt of $3600 and a standard deviation of $391. At =0.10, can the credit agency's claim be supported, assuming this is a normally distributed data set?

Yes, since p-value of 0.13 is greater than 0.10, fail to reject the null. Claim is null, so is supported

No, since p-value of 0.13 is greater than 0.10, reject the null. Claim is null, so is not supported

Yes, since p-value of 0.13 is less than 0.55, reject the null. Claim is alternative, so is supported

No, since p of 0.13 is greater than 0.10, fail to reject the null. Claim is alternative, so is not supported

Question

19

2pts

A car company claims that its cars achieve an average gas mileage of at least 26 miles per gallon. A random sample of five cars form this company have an average gas mileage of 25.2 miles per gallon and a standard deviation of 1 mile per gallon. At =0.06, can the company's claim be supported, assuming this is a normally distributed data set?

No, since the test statistic of -1.79 is close to the critical value of -2.60, the null is not rejected. The claim is the null, so is supported

Yes, since the test statistic of -1.79 is not in the rejection region defined by the the critical value of -2.60, the null is rejected. The claim is the null, so is supported

No, since the test statistic of -1.79 is in the rejection region defined by the critical value of -1.97, the null is rejected. The claim is the null, so is not supported

Yes, since the test statistic of -1.79 is not in the rejection region defined by the critical value of -1.97, the null is not rejected. The claim is the null, so is supported

Question

20

2pts

A researcher wants to determine if extra homework problems help 8th grade students learn algebra. One 8th grade class has extra homework problems and another 8th grade class does not. After 2 weeks, the both classes take an algebra test and the results of the two groups are compared. To be a valid matched pair test, what should the researcher consider in creating the two groups?

That each class has similar average IQs or abilities in mathematics

That the group with the extra homework problems has fewer after school activities

That the group without extra homework problems receives different instruction

That each class of students has similar ages at the time of the testing

.