Questions 12.82, 12.84 and 12.86 are to be answered only

Assignment 3 Do 12.82, 12.84, 12.86 Developing an Understanding of Statistical Concepts c. Repeat part (a) with n = 400. Exercises 12.82 to 12.85 are "what-if analyses" designed to deter- d. Describe the effect on the p-value of increasing mine what happens to the test statistics and interval estimates the sample size. when elements of the statistical inference change. These prob- 12.85 a. A statistics practitioner wants to test the follow- lems can be solved manually or using your Do-It-Yourself Excel ing hypotheses: spreadsheets. Ho: P = .70 12.82 a. In a random sample of 200 observations, we H1: p> .70 found the proportion of successes to be 48%. Estimate with 95% confidence the population A random sample of 100 produced p = .73. proportion of successes. Calculate the p-value of the test. b. Repeat part (a) with n = 500. b. Repeat part (a) with p = .72. c. Repeat part (a) with n = 1000. c. Repeat part (a) with p = .71. d. Describe the effect on the confidence interval d. Describe the effect on the z-statistic and its estimate of increasing the sample size. p-value of decreasing the sample proportion. 12.83 a. The proportion of successes in a random sample 12.86 Determine the sample size necessary to estimate of 400 was calculated as 50%. Estimate the pop- a population proportion to within .03 with 90% ulation proportion with 95% confidence. confidence assuming you have no knowledge of the b. Repeat part (a) with p = 33%. approximate value of the sample proportion. c. Repeat part (a) with p = 10%. 12.87 Suppose that you used the sample size calculated in d. Discuss the effect on the width of the confidence Exercise 12.86 and found p = .5. interval estimate of reducing the sample proportion. a. Estimate the population proportion with 90% 12.84 a. Calculate the p-value of the test of the following confidence. hypotheses given that p = .63 and n = 100: b. Is this the result you expected? Explain. Ho: P= .60 12.88 Suppose that you used the sample size calculated in H1: p > .60 Exercise 12.86 and found p = .75. a. Estimate the population proportion with 90% b. Repeat part (a) with n = 200. confidence. b. Is this the result you expected? Explain. used statistical inference within one year of c. If you were hired to conduct this analysis, would tion. Estimate with 90% confidence the pro the person who hired you be satisfied with the of all business school graduates who use thei interval estimate you produced? Explain. tical education within a year of graduation