a) X and Y are two discrete random variables with joint probability function f(x,y) given by f(x,y) = (x+y)/32; x = 1, 2; y = 1, 2, 3, 4
i) Find the marginal p.f.’s of X and Y.
ii) Find P(X > Y).
iii) Find P(Y = 2X).
iv) Are X and Y independent? Give a reason for your answer.
b) Two continuous random variables X and Y have joint probability density function f(x,y) given by f(x,y) = { kx^2(1 + 2y); 0 ≤ x ≤ 2; 0 ≤ y ≤ 2; 0 otherwise
i) Find the value of k.
ii) Find P(Y < 2X).
iii) Find E(XY).
iv) Find the marginal p.d.f.’s of X and Y.
v) Find Cov(X,Y).
vi) Are X and Y independent? Give a reason for your answer.