A portfolio manager summarizes the input from the macro and micro forecasters in the following table: Asset Stock A Stock 8 Stock 6 Stock D Micro Forecasts Expected Residual Standard Return (%) Beta Deviation (%) 20 1.3 58 18 1.8 71 17 0.7 60 12 1.0 55 Macro Forecasts Expected Standard Asset Return (%) Deviation (%) T-bills 8 0 Passive equity portfolio 16 23 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 C Stock 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