Question 11

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 2.6 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?

A)Claim is null, reject the null and cannot support claim as test statistic (-1.78) is not in the rejection region defined by the critical value (-2.05)

B)Claim is alternative, reject the null and support claim as test statistic (-1.78) is not in the rejection region defined by the critical value (-2.05)

C)Claim is null, fail to reject the null and cannot support claim as test statistic (-1.78) is not in the rejection region defined by the critical value (-2.05)

D)Claim is alternative, fail to reject the null and cannot support claim as test statistic (-1.78) is not in the rejection region defined by the critical value (-2.05)

Question 12

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 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?

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

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

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

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

Question 13

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 48 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?

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

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

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

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

Question 14

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 46.5 minutes. Assuming a population standard deviation of 5.2 minutes, can the company support the cleaning service's claim at =0.10?

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

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

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

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

Question 15

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 0.29 minutes. Can the claim be supported at =0.08?

A)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

B)No, 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 not supported

C)Yes, 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 supported

D)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