1. Let Y be a random variable with expectation 0 and variance ov. Let Z1, Z2,... be an iid sequence with expectation 0 and variance oz, where all the Zs are independent from Y. Let Xi = Y+Zi and Wn = XitXz+ . + Xn. (a) Find E[X;], Var[X;], and Cov[Xi, X;] for i # j. (b) Find E[W,] and Var[W, ]