19. a. Suppose the continuous random variable X has the probability density function f (20 ) = c(42 + 620), 3 ( [0, 2] otherwise for some constant c. i. What is E(X)? ii. Calculate Pr(X >> 1.5). b. Suppose the continuous random vector (X, Y) has the joint probability distribution f (x , y) = 1 0, c(4my + y?), = = [0, 1], y E [0, 1] otherwise for some constant c. i. Calculate Pr(X + Y > 1.5). ii. Calculate E(Y). iii. What is Cov (X, Y)? iv. What is f(ay), the conditional probability density function of a given y? v. Compute E(X Y) = 0.5