2. A simple random sample of a population of size 1000 yields the following 25 values:

92;92;94;94;95;97;97;97;98;98;99;99;100;101;101;102;102;103;103;103;105;106;106;108;108

(a) Calculate unbiased estimates of the population mean and population variance.

(b) We know from past testing that the population standard deviation is 0.9. Give approximate 95% and 99% confidence intervals for the population mean