The Engineering Department at Sims Software Inc. recently developed two chemical solutions designed to increase the usable life of computer disks.

A sample of disks treated with the first solution lasted 86, 88, 66, 83, 84, 81, 94, 109, 65, and 102 hours.

Those treated with the second solution lasted 91, 71, 75, 76, 77, 79, 73, 76, 79, 78, 87, 80, 76, and 72 hours.

Assume the population standard deviations are the same.

At the .05 significance level, can we conclude that there is a difference in the length of time the two types of treatment lasted?

A. The variable of interest (x) in this problem is the usable life of computer disks given the type of chemical solution used.

a. True

b. False

B. The problem involves:

a. Comparing the proportions of two populations

b. Comparing the variances of two populations

c. Comparing the means of two dependent populations

d. Comparing the means of two independent samples

e. None of the above

C. What is the correct hypothesis setup for this problem?

a. H0: First = Second H1: First Second

b. H0: First Second H1: First > Second

c. H0: First Second H1: First < Second

d. H0: First Second H1: First > Second

e. H0: First Second H1: First < Second

f. None of the above

D. What is the average usable life of the disks for First Solution (round to four decimals)? ________

E. What is the average usable life of the disks for Second Solution (round to four decimals)? ________

F. The computed test statistic for the sample above is ________ (round to 4 decimals).

G. At the 0.05 significance level, what is the critical value for testing the null hypothesis?_________

H. What is the p-value for the test? _____________ (round to 4 decimals).

I. At the 0.05 significance level, what is the correct statistical conclusion?

a. Reject the null hypothesis

b. Fail to reject the null hypothesis

c. Reject the alternate hypothesis

d. Fail to reject the alternate hypothesis

e. None of the above. The test is inconclusive

J. Based on the result of the statistical test above, which of the following would be the correct conclusion?

a. There is no difference in the average useful life of the disks for two types of solutions. Both are equally effective.

b. There is a difference in the average useful life of the disks for two types of solutions - the disks using the First Solution lasted longer.

c. There is a difference in the average useful life of the disks for two types of solutions - the disks using the Second Solution lasted longer.

d. There is not enough data to make a conclusion.

e. None of the above