I Consider a job that has a sample mean time of 17 minutes and a sample standard deviation time of 4 minutes. Firstly, determine the number of observations required to achieve a maximum error of 5% of the sample mean if the desired confidence level is 90% (i.e., Z = 1.65). z S minutes a s T minutes n observations Secondly, determine the number of observations required to achieve a maximum error of 0.7 minutes if the desired confidence level is 90% (i.e., z = 1.65). e minutes n observations