A random sample of 12 employees in a large manufacturing plant found the following figures for number of hours of overtime worked in the last month:
22 16 28 12 18 36 23 11 41 29 26 31
Use unbiased estimation procedures to find point estimates for the following:
a. The population mean
b. The population variance
c. The variance of the sample mean
d. The population proportion of employees working more than 30 hours of overtime in this plant in the last month.