Problem 3.26. Three brands of batteries are under study. It is suspected that the lives (in...

Problem 3.26.

Three brands of batteries are under study. It is suspected that the lives (in weeks) of the three brands are different. Five randomly selected batteries of each brand are tested with the following results:

	Weeks of Life
Brand 1	Brand 2	Brand 3
100	76	108
96	80	100
92	75	96
96	82	100
92	82	100

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

b) Analyze the residuals from this experiment.

c) Construct a 95 percent conﬁdence interval estimate on the mean life of battery brand 2. Construct a 99 percent 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?

Expert Solution

orchestra answered 1 year ago

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