Given the estimated regression equations in which C, Y and R denote consumption, income and interest rates respectively; Ct = ao + 0.90 Z Ct = bo - 0.80 Rt Rt = Co + 0.70 Z Z = do - 0.50 Rt Calculate the OLS estimates of e, and ez for the following regression; Ct = eo + e1 Zt + ez Rt + Ut