Let X and Y be independent random variables. X can take on values 0, 1, 2 and P(X= 0) = 1/2, P(X = 1) = 1/4 and P(X = 2) = 1/4. About r.v. Y we know that it can take on values -1 and 1, and P(Y = −1) = 1/2 and P(Y = 1) = 1/2.
(a) Find joint pmf for X and Y.
(b) Find mean and variance for r.v. X and Y.
(c) Find covariance for r.v. X and Y.
