Suppose that X, Y, wnd Z ure ontly dstrbuted randum yariables, that is, they are detined on the same sample space. Suppose that we also have the following. EX) -4 E(Z) --9 E(Y)-2 Var (X)-26 l'ar(Y)-45 Var (2) - 39 Compute the values of the expressions below. E(-4- r) - 0 For(-a) - -0