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Unformatted text preview: Chapter 8 Hypothesis Testing True/False 1. The further the hypothesized mean is from the actual mean the greater the power of the test. Answer: True Difficulty: Medium (REF) 2. The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. She knows the population standard deviation and uses a Z test to test the null hypothesis that the mean tensile strength is 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a pvalue of .067 for the test. If the significance level is .10, the null hypothesis would be rejected. Assume that the population of pressure values is normally distributed. Answer: False Difficulty: Medium Use the following information to answer questions 34: The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. The population is normally distributed and the population standard deviation is known. She uses a Z test to test the null hypothesis that the mean tensile strength is less than or equal to 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a pvalue of .067 for the test. 3. If the significance level is .10, the null hypothesis would be rejected. Answer: True Difficulty: Medium 4. If the significance level is .05, the null hypothesis would be rejected. Answer: False Difficulty: Medium Use the following information to answer questions 56: The manager of the quality department for a tire manufacturing company wants to know the average tensile strength of rubber used in making a certain brand of radial tire. The population is normally distributed and the population standard deviation is known. She uses a Z test to test the null hypothesis that the mean tensile strength is 800 pounds per square inch. The calculated Z test statistic is a positive value that leads to a pvalue of .045 for the test. 5. If the significance level ( α ) is .01, the null hypothesis would be rejected. Answer: False Difficulty: Medium Bowerman, Essentials of Business Statistics, 2/e 226 6. If the significance level ( α ) is .05, the null hypothesis would be rejected. Answer: True Difficulty: Medium 7. A Type I error is rejecting a true null hypothesis. Answer: True Difficulty: Medium 8. The larger the pvalue, the more we doubt the null hypothesis. Answer: False Difficulty: Medium 9. A Type II error is failing to reject a false null hypothesis. Answer: True Difficulty: Medium (REF) 10. You cannot make a Type II error when the null hypothesis is true. Answer: True Difficulty: Medium (REF) 11. For a hypothesis test about a population proportion or mean, if the level of significance is less than the pvalue, the null hypothesis is rejected....
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 Spring '07
 Lv
 Null hypothesis, Statistical hypothesis testing, Bowerman, Difficulty

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