A sociologist found that in a random sample of 50 retired men, the average number of jobs they had during their lifetimes was 7.2. The population standard deviation is 2.1
Find the 99% confidence interval of the mean number of jobs. Do not round the z value, it should have two decimal places, example 2.34. Round the interval to one decimal place, example 3.2 < μ < 5.6