A portfolio manager summarizes the input from the macro and micro forecasters in the following table: Micro Forecasts Residual Standard Expected Asset Return () Beta Deviation () Stock A Stock B Stock C 21 stock D 25 22 1.6 2.2 1.4 1.5 50 58 16 43 Macro Forecasts Expected Standard Deviation Return Asset r-bills Passive equity portfolio 12 18 30 a. Calculate expected excess returns, alpha values, and residual variances for these stocks. (Negative values should be indicated by a minus sign. Do not round intermediate calculations. Round "Alpha values" to 1 decimal place.) Stock A Stock B Stock CStock D Excess returns Alpha values Residual variances b. Compute the proportion in the optimal risky portfolio. (Do not round intermediate calculations. Enter your answer as decimals rounded to 4 places.) Proportion