19)An insurance company is trying to estimate the average number of sick days that full time food service workers use per year. A standard deviation to be 4.5 days. How large of a sample must be selected the company wants to be 95% confident of getting an interval that contains the true mean with a maximum error of two days? pilot study found the 20) The mean salary of federal government employees is $84,200. The average salary of 64 state employees with a similar job is $81,780 with a standard deviation of $8,800. At a level of significance of 0.02, can we conclude that state employees earn, on average, less than federal employees