(a) Consider a nonnegative, integer valued random variable Y, and a random sample X1, - - - , X ,1. Assume Y and all the Xj's are independent. Find E(X1 + - - - + Xy) in terms of E(X1) and E(Y). (b) Suppose each person who logs onto Amazoneom on Christmas Eve is expected to spend $80. One hundred people are randomly chosen to see how much is spent by them. Each of them visits Amazon.eom with probability 60%. How much money do we expect this group of people to spend at Amazon.com