(15 points) Problem #16. For each trip to the grocery store, a shopper spends an average of u=40 minutes with a standard deviation of o =14 minutes. The length of time spent in the store is normally distributed. (a) If one randomly chosen shopper is selected, what is the probability that his/her shopping time is within 10 minutes of the population mean? Normal cdf ( 30, 50 , 4 0, 14 ) = 52. 4949 % that If one randomly chosen shopper is selected the shopping time will be 10 min of population mean. (b) Suppose random samples each consisting of 15 shoppers is selected and the mean time spent shopping is calculated for each sample of 15. What is the sampling distribution of the sample means? Justify your answer. BE SPECIFIC AND USE CLEAR, COMPLETE SENTENCES