4.4-2 Let f (x,y) =x+y, O

4.4-2 Let f (x, y) =x+Y, 0 s x S l, 0 S y S I , be the joint pdf of X and Y. (a) Find the marginal pdfs and fy(v) , and show that f (x, y) (x) f (y) . Thus X and Y are dependent. (b) Compute the means and variances of X and Y.