Let X, and Y be two independent random variables such that E(X)=2, Var(X)=4, E(Y)=7. and Var(Y)=1. Find: E(3X+7) A. 13 B.19 C. 28 D. 6 O A OC OD O BLet X and Y be discrete random variables with joint probability function P(I, y) = 12 21+2 for (x, y) = (0, 1), (0, 2), (1, 2), (1,3), otherwise. Determine the marginal probability function of X. 1/6 for = = 0, (A) p(x) = 5/6 for z = 1, 0 otherwise. 1/4 for a = 0, (B) p(x) = 3/4 for z = 1, 0 otherwise. 1/3 for = = 0, (C) p(I) = (2/3 for = = 1, 0 otherwise. 2/9 for 1 = 1, (D) p(I) = 3/9 for 1 = 2. 4/9 for = = 3, 0 otherwise. y/12 for = = 0, (E) p(x) =