i) If E[X] = 1.7 and Var [X] = 2.25 and Y = 2X + 4 what are E[Y] and Var(Y]? ii) If Xt+1 = o(Xt - u) + et, where u is a constant, Var[Xtti] = Var[Xt] = o2 and Varlet] = 02, derive the formula for of in terms of o, / and oz