Let X1 and X2 denote the proportions of time, out of one workweek, that employees I and II, respectively, actually spend perform
ing their assigned tasks. The joint relative frequency behavior of X1 and X2 is modeled by the pdf f(x1, x2) = ( x1 + x2 for 0 ≤ x1 ≤ 1, 0 ≤ x2 ≤ 1 ), 0 otherwisea). Find Cov(X1, X2).b). Find E(3X1 − 2X2).c). Find V (3X1 − 2X2).
