Chapter 13

Two brands of car batteries, both carrying 6-year warranties, were sampled and tested under controlled conditions. Five of each brand failed after the numbers of months shown here. Brand A: 75, 65, 70, 64, 71. Brand B: 69, 70, 62, 72, 60 (a) Calculate both Brands means. Brand A mean= Brand B mean= (b) Calculate both brands standard deviations. ................
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