In order to control costs, a company wishes to study the amount of money its sales force spends entertaining clients. The following is a random sample of six entertainment expenses (dinner costs for four people) from expense reports submitted by numbers of the sales force.
$157 $132 $ 109 $145 $125 $139
Calculate Mean, Variance, and Standard Deviation. Assuming that the distribution on entertainment expenses is approximately normally distributed, calculate estimate of tolerances interval containing 95.44%