Suppose X is a Gaussian (1, 1) random variable and K is an independent discrete random variable with PMF
Let X1, X2,... denote a sequence of iid random variables each with the same distribution as X.
(a) What is the MGF of K?
(b) What is the MGF of R = X1 +···+ XK? Note that R = 0 if K = 0.
(c) Find E[R] and Var[R].