Suppose that X, Y, and Z are jointly distributed random variables, that is, they are defined on the same sample space. Suppose that we also have the following. E (Z) =-4 Var (X) = 19 Var (Y)= 27 Var (z) = 21 E(X) = 3 E(Y) =-7 Compute the values of the expressions below. E(3 + 2x) - || -2X - 42 E -5 Var (1 - 3Y) - I E(-2x) - D