(b) Let {Xi, i = 1,..., n} be independent random variables given by the Bernoulli distribution with probability of success p E (0, 1), that is P(X; = 1) =p, P(X; = 0) = 1 -p. Let Sn = X1 + X2+ . .. + Xn for n > 1. Derive the moment generating function Ms,, for Sn