5. A sociologist found that in a random sample of n = 50 retired men, the sample mean (xbar) number of jobs they had during their lifetimes was 7.2. They found the distribution is normally distributed with a population standard deviation o of 2.1. (a) What is the point estimate of the population mean? What is the value of the population mean? (b) Using the 90 percent level of confidence, determine the confidence interval for p. (c) Provide an interpretation for the estimated confidence interval in part b