Probability and Statistics for Engineering and the Sciences
9th Edition
ISBN: 9781305251809
Author: Jay L. Devore
Publisher: Cengage Learning
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Textbook Question
Chapter 9.5, Problem 64E
The following observations are on time (h) for a AA 1.5- volt alkaline battery to reach a 0.8 voltage (“Comparingthe Lifetimes of Two Brands of Batteries,” J. of Statistical Educ., 2013, online):
| Energizer: | 8.65 | 8.74 | 8.91 | 8.72 | 8.85 |
| Ultracell: | 8.76 | 8.81 | 8.81 | 8.70 | 8.73 |
| Energizer: | 8.52 | 8.62 | 8.68 | 8.86 | |
| Ultracell: | 8.76 | 8.68 | 8.64 | 8.79 |
Normal probability plots support the assumption that the population distributions are normal. Does the data suggest that the variance of the Energizer population distribution differs from that of the Ultracell population distribution? Test the relevant hypotheses using a significance level of .05. [Note: The two-sample t test for equality of population means gives a P-value of .763.] The Energizer batteries are much more expensive than the Ultracell batteries. Would you pay the extra money?
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Chapter 9 Solutions
Probability and Statistics for Engineering and the Sciences
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