11.A computer manufacturer estimates that its cheapest screenswill last less than 2.8 years. A random sample of 61 of thesescreens has a mean life of 2.5 years. The population is normallydistributed with a population standard deviation of 0.88 years. Atα=0.02, what type of test is this and can you support theorganization’s claim using the test statistic?
Claim is alternative, reject the null and support claim as teststatistic (-2.66) is in the rejection region defined by the thecritical value (-2.05)
Claim is alternative, fail to reject the null and cannot supportclaim as test statistic (-2.66) is in the rejection region definedby the critical value (-2.05)
Claim is null, reject the null and support claim as teststatistic (-2.66) is in the rejection region defined by thecritical value (-2.05)
Claim is null, fail to reject the null and cannot support claimas test statistic (-2.66) is in the rejection region defined by thecritical value (-2.05)
12. A pharmaceutical company claims that the average cold lastsan average of 8.4 days. They are using this as a basis to test newmedicines designed to shorten the length of colds. A random sampleof 106 people with colds, finds that on average their colds last8.28 days. The population is normally distributed with a standarddeviation of 0.9 days. At α=0.02, what type of test is this and canyou support the company’s claim using the p-value?
Claim is null, reject the null and cannot support claim as thep-value (0.170) is less than alpha (0.02)
Claim is null, fail to reject the null and support claim as thep-value (0.170) is greater than alpha (0.02)
Claim is alternative, fail to reject the null and support claimas the p-value (0.085) is less than alpha (0.02)
Claim is alternative, reject the null and cannot support claimas the p-value (0.085) is greater than alpha (0.02)
13. A business receives supplies of copper tubing where thesupplier has said that the average length is 26.70 inches so thatthey will fit into the business’ machines. A random sample of 48copper tubes finds they have an average length of 26.77 inches. Thepopulation standard deviation is assumed to be 0.20 inches. Atα=0.05, should the business reject the supplier’s claim?
No, since p>α, we reject the null and the null is theclaim
No, since p>α, we fail to reject the null and the null is theclaim
Yes, since p>α, we fail to reject the null and the null isthe claim
Yes, since p<α, we reject the null and the null is theclaim
14. The company’s cleaning service states that they spend morethan 46 minutes each time the cleaning service is there. Thecompany times the length of 37 randomly selected cleaning visitsand finds the average is 47.2 minutes. Assuming a populationstandard deviation of 5.2 minutes, can the company support thecleaning service’s claim at α=0.10?
Yes, since p>α, we reject the null. The claim is the null, sothe claim is not supported
Yes, since p<α, we fail to reject the null. The claim is thenull, so the claim is not supported
No, since p>α, we fail to reject the null. The claim is thealternative, so the claim is not supported
No, since p<α, we reject the null. The claim is thealternative, so the claim is supported
15.. A customer service phone line claims that the wait timesbefore a call is answered by a service representative is less than3.3 minutes. In a random sample of 62 calls, the average wait timebefore a representative answers is 3.26 minutes. The populationstandard deviation is assumed to be 0.29 minutes. Can the claim besupported at α=0.08?
No, since test statistic is not in the rejection region definedby the critical value, reject the null. The claim is thealternative, so the claim is not supported
Yes, since test statistic is in the rejection region defined bythe critical value, reject the null. The claim is the alternative,so the claim is supported
Yes, since test statistic is in the rejection region defined bythe 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 definedby the critical value, fail to reject the null. The claim is thealternative, so the claim is not supported
