Independent random samples from four different brands of recently produced batteries were placed

on a life test. The following lifetimes (in minutes) were recorded.

Brand A Brand B Brand C Brand D

110 118 108 117

113 116 107 112

108 112 112 115

115 117 108 119

112 119 109 118

a) Provide an outline for the design of this experiment.

b) Identify the response variable.

c) develop graph for this data. Can you see a difference in the average lifetime of these four brands?

d) Is there any evidence that the sample data contradicts the claim that there are no differences in the

average lifetime of these four brands?