Jobs and productivity! How do retail stores rate? One way to answer this question is to examine annual profits per employee. The following data give annual profits per employee (in units of one thousand dollars per employee) for companies in retail sales. Assume cr 2 3.5 thousand dollars. 4.5 6.0 3.9 8.6 8.2 5.3 8.0 5.9 2.6 2.9 8.1 1.9 11.9 8.2 6.4 4.7 5.5 4.8 3.0 4.3 6.0 1.5 2.9 4.8 1.7 9.4 5.5 5.8 4.7 6.2 15.0 4.1 3.7 5.1 4.2 (a) Use a calculator or appropriate computer software to find E for the preceding data. (Round your answer to two decimal places.) E thousand dollars per employee (b) Let us say that the preceding data are representative of the entire sector of retail sales companies. Find an 80% confidence interval for p, the average annual profit per employee for retail sales. (Round your answers to two decimal places.) lower limit 3 thousand dollars upper limit E thousand dollars (c) Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b). 0 Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores. 0 No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores. (d) Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b). 0 Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores. 0 No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores. (e) Find an 95% confidence interval for [.t, the average annual profit per employee for retail sales. (Round your answers to two decimal places.) lower limit 3 thousand dollars upper limit E thousand dollars Let us say that you are the manager of a retail store with a large number of employees. Suppose the annual profits are less than 3 thousand dollars per employee. Do you think this might be low compared with other retail stores? Explain by referring to the confidence interval you computed in part (b). 0 Yes. This confidence interval suggests that the profits per employee are less than those of other retail stores. 0 No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores. Suppose the annual profits are more than 6.5 thousand dollars per employee. As store manager, would you feel somewhat better? Explain by referring to the confidence interval you computed in part (b). 0 Yes. This confidence interval suggests that the profits per employee are greater than those of other retail stores. 0 No. This confidence interval suggests that the profits per employee do not differ from those of other retail stores. Suppose x has a distribution with i4 = 28 and a = 26. (a) If a random samp e of size n = 39 is drawn, find it}, a; and P(28 5 ; s 30). (Round :7; to two decimal places and the probability to four decimal places.) #;= 28 a; = 4.16 P(28 s 2 s 30) = (b) If a random sample of size n = 70 Is drawn, find it}, a; and P(28 5 5 30). (Round 6; to two decimal places and the probability to four decimal places.) a; = 3.11 P(285;330)=I: (c) Why should you expect the probability of part (b) to be higher than that of part (a)? (Hint: Consider the standard deviations in parts (a) and (b).) The standard deviation of part (b) is largerthan v part (a) because of the sample size. Therefore, the distribution about u; is . Need Help? Viewing Saved Work Revert to Last Response (3 Points] DETAILS PREVIOUS ANSWERS BBRIEFSTAT5 7.5.012. MY NOTES | PRACTICE ANOTHER Suppose the heights of 18-year-old men are approximately normally distributed, with mean 65 inches and standard deviation 6 inches. (a) What is the probability that an 18year-old man selected at random is between 64 and 66 inches tall? (Round your answer to four decimal places.) .1350 (b) If a random sample of fourteen 18year-old men is selected, what is the probability that the mean height ; is between 64 and 66 inches? (Round your answer to four decimal places.) .3400 x lJ El Let x be a random variable that represents white blood cell count per cubic milliliter of whole blood. Assume that x has a distribution that Is approximately normal, with mean M = 7200 and estimated standard deviation 0 = 2400. A test result of X