e Ur WORKED PROBLEMS – SHOW CALCULATIONS IN ORDER TO CEL ULL CREDIL BIS 509 AN 04 60 t N nd 87 1. The personnel director of a large corporation wants to study absenteeism among clerical workers at the corporation's central office during the year. A random sample of 25 clerical workers reveals the following: [20 points] ☐ Absenteeism: X = 9.7 days, S = 4.0 days. 12 clerical workers were absent more than 10 days. a. Set up a 95% confidence interval estimate of the average number of absences for clerical workers last year. b. Set up a 95% confidence interval estimate of the population proportion of clerical workers absent more than 10 days last year. c. If the personnel director also wants to take a survey in a branch office, what sample size is needed if the director wants to be 95% confident of being correct to within ± 1.5 days and the population standard deviation is assumed to be 4.5 days? d. If the personnel director also wants to take a survey in a branch office, what sample size is needed if the director wants to be 90% confident of being correct to within ± 0.075 of the population proportion of workers who are absent more than 10 days if no previous estimate is available? new