Question 3 (15 pts). A simple random sample of a population of size 1000 yields the following 20 values: 22, 23, 24, 24, 25, 27, 27, 27, 28, 30, 31, 32, 32, 33, 33, 33, 35, 38, 40, 40. (a) Calculate unbiased estimates of the population mean and population variance. (b) We know from past testing that the population standard deviation is 1. Give ap- proximate 95% and 99% confidence intervals for the population mean