If the average amount of time customers spent online at an Internet retailer's site is assumed to be normally distributed with mean of 36 minutes and a standard deviation of 6 minutes, determine a. the probability a customer spends less than 30 minutes on the site b. the probability a customer spends more than 44 minutes on the site c. the probability a customer spends between 33 and 42 minutes on the site d . the amount of time in minutes spent on the site by no more than 5% of all customers