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10 SBE11e SM Ch10 1

Satisfactory Essays

Chapter 10 Statistical Inference About Means and Proportions with Two Populations Learning Objectives 1. Be able to develop interval estimates and conduct hypothesis tests about the difference between two population means whenandare known. 2. Know the properties of the sampling distribution of . 3. Be able to use the t distribution to conduct statistical inferences about the difference between two population means whenandare unknown. 4. Learn how to analyze the difference between two population means when the samples are independent and when the samples are matched. 5. Be able to develop interval estimates and conduct hypothesis tests about the difference between two population proportions. 6. Know the properties of the sampling …show more content…

Penney. 9. a. = 22.5 - 20.1 = 2.4 b. Use df = 45. c. t.025 = 2.014 d. 2.4 2.1 (.3 to 4.5) 10. a. b. Use df = 65 c. Using t table, area in tail is between .01 and .025 two-tail p-value is between .02 and .05. Exact p-value corresponding to t = 2.18 is .0329 d. p-value .05, reject H0. 11. a. b. c. = 9 - 7 = 2 d. Use df = 9, t.05 = 1.833 2 2.17 (-.17 to 4.17) 12. a. = 22.5 - 18.6 = 3.9 b. Use df = 87, t.025 = 1.988 3.9  (.6 to 7.2) 13. a. b. = 9.3 - 4.2 = 5.1 tons Memphis is the higher volume airport and handled an average of 5.1 tons per day more than Louisville. Memphis handles more than twice the volume of Louisville. c. Use df = 17, t.025 = 2.110 5.1  1.82 (3.28 to 6.92) 14. a. H0: Ha: b. c. = 87.55 Rounding down, we will use a t distribution with 87 degrees of freedom. From the t table we see that t = -2.41 corresponds to a p-value between .005 and .01. Exact p-value corresponding to t = -2.41 is .009. d. p-value .05, reject H0. We conclude that the salaries of staff nurses are lower in Tampa than in Dallas. 15. 1 for 2001 season 2 for 1992 season H0: Ha: b. = 60 - 51 = 9 days 9/51(100) = 17.6% increase in number of days. c. Using t table, p-value is between .005 and .01. Exact p-value corresponding to t = 2.48 is .0076 p-value .01,

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