Question

These brands of batteries are under study. It is suspected that the lives (in weeks) of these brands are different. Five randomly selected batteries of each brand are tested with the following results: (Please answer using Sas, also if you don't want to answer a-d, could you just answer (a.) and (c.). If you also want to do (b.) and (d.), that would be stellar. Also please answer with Sas.)

Weeks of life:

Brand 1 | Brand 2 | Brand 3

100 | 76 | 108

96 | 80 | 100

92 | 75 | 96

96 | 84 | 98

92 | 82 | 100

a.) Are the lives of these brands of batteries different?

b.) Analyze the residuals

c.) Construct a 95% confidence interval estimate on the mean life of battery brand 2. Construct a 99% confidence interval estimate on the mean difference between the lives of battery brands 2 and 3.

d.) Which brand would you select for use? If the manufacturer will replace without charge any battery that fails in less than 85 weeks, what percentage would the company expect to replace?

Answer 1