The joint p.m.f. of X and Y is f(x, y) = 1/6, 0 ≤ x + y ≤ 2, where x and y

Question

are nonnegative integers.
(a) Sketch the support of X and Y.
(b) Record the marginal p.m.f.’s f1(x) and f2(y) in the “margins.”
(c)Compute Cov(X, Y).
(d)Determine ρ,the correlation coefficient.