TRY IT YOURSELF ANSWERS A41 5. There is not enough evidence at the 1% level of significance to support the claim that the mean number of workdays missed due to illness or injury in the past 12 months is 3.6 days. 6. Fail to reject H0. 7. z0 = -1.28; Rejection region: z 6 -1.28 8. -z0 = -1.75, z0 = 1.75 Rejection regions: z 6 -1.75, z 7 1.75 9. There is enough evidence at the 1% level of significance to support the claim that the mean workday is less than 8.5 hours. 10. There is not enough evidence at the 1% level of significance to reject the claim that the mean cost of raising a child between the ages of 1 and 3 in the United States is $13,350. Section 7.3 1. -2.650 2. 1.397 3. -2.131, 2.131 4. There is enough evidence at the 10% level of significance to support the analyst’s claim that the mean transaction price of new vehicles sold in the last 12 months is less than $43,500. 5. There is enough evidence at the 1% level of significance to reject the company’s claim that the mean conductivity of the river is 1890 milligrams per liter. 6. There is not enough evidence at the 5% level of significance to reject the office’s claim that the mean wait time is at most 18 minutes. Section 7.4 1. There is not enough evidence at the 1% level of significance to support the researcher’s claim that more than 36% of U.S. adults would consider buying a product or service directly from an advertisement that is run during streaming programming. 2. There is enough evidence at the 10% level of significance to reject the researcher’s claim that 70% of U.S. adults ages 22 to 59 who have at least one parent with a bachelor’s degree or more education have completed a bachelor’s degree themselves. Section 7.5 1. x 2 = 33.409 2. x 2 = 17.708 3. x2 L = 27.991, x 2 R = 79.490 4. There is enough evidence at the 1% level of significance to reject the bottling company’s claim that the variance of the amount of sports drink in a 12-ounce bottle is no more than 0.40. 5. There is not enough evidence at the 5% level of significance to support the police chief’s claim that the standard deviation of the lengths of response times is less than 3.7 minutes. 6. There is enough evidence at the 10% level of significance to reject the company’s claim that the variance of the weight losses of the users is 25.5. Chapter 8 Section 8.1 1. (1) Independent (2) Dependent 2. There is enough evidence at the 10% level of significance to support the claim that there is a difference in mean annual wages. 3. There is not enough evidence at the 5% level of significance to support the claim that the average monthly rent for a one-bedroom apartment in Atlanta, GA, is greater than the average monthly rent for a one-bedroom apartment in Nashville, TN. Section 8.2 1. There is enough evidence at the 5% level of significance to support the claim that there is a difference in the mean annual earnings based on level of education. 2. There is not enough evidence at the 10% level of significance to support the manufacturer’s claim that the mean driving cost per mile of its minivans is less than that of its leading competitor. Section 8.3 1. There is enough evidence at the 10% level of significance to support the claim that people who play golf can improve (decrease) their average golf scores by using the company’s newly designed golf clubs. 2. There is not enough evidence at the 5% level of significance to support the claim that the drug changes the body’s temperature. Section 8.4 1. There is not enough evidence at the 5% level of significance to support the claim that there is a difference between the proportion of people who use yoga who are 40- to 49-year-olds and the proportion of people who do not use yoga who are 40- to 49-year-olds. 2. There is enough evidence at the 5% level of significance to reject the claim that the proportion of people who use yoga who are from the western region of the United States is greater than or equal to the proportion of people who do not use yoga who are from the western region of the United States.
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