A portfolio manager summarizes the input from the macro and micro forecasters in the following table:

Micro Forecasts
Asset	Expected Return (%)			Beta	Residual Standard Deviation (%)
Stock A		25		0.8		52
Stock B		19		1.2		61
Stock C		16		0.6		55
Stock D		12		0.7		47

Macro Forecasts
Asset	Expected Return (%)			Standard Deviation (%)
T-bills		8			0
Passive equity portfolio		18			26

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:

c. What is the Sharpe ratio for the optimal portfolio? (Do not round intermediate calculations. Enter your answers as decimals rounded to 4 places.)

Sharpe ratio:

d. By how much did the position in the active portfolio improve the Sharpe ratio compared to a purely passive index strategy? (Do not round intermediate calculations. Enter your answers as decimals rounded to 4 places.)

Active portfolio