Problem 6-20 Refer the table below on the average risk premium of the S&P 500 over T-bills and the standard deviation of that risk premium. Suppose that the S&P 500 is your risky portfolio. Period 1926-2015 1992-2015 1970-1991 1948-1969 1926-1947 Average Annual Returns S&P 580 1- Month Portfolio T-Bills 11.77 3.47 10.79 2.66 12.87 7.54 14.14 2.70 9.25 @.91 Risk Premium 8.30 8.13 5.33 11.44 8.33 S&P 500 Portfolio Standard Deviation 20.59 18.29 18.20 17.67 27.99 Sharpe Ratio 0.40 8.44 0.29 0.65 8.30 a. If your risk-aversion coefficient is A = 3.9 and you believe that the entire 1926-2015 period is representative of future expected performance, what fraction of your portfolio should be allocated to T-bills and what fraction to equity? Assume your utility function is U = E1-0.5 A0? (Do not round intermediate calculations. Round your answers to 2 decimal places.) T-bills Equity b. If your risk-aversion coefficient is A = 3.9 and you believe that the entire 1970-1991 period is representative of future expected performance, what fraction of your portfolio should be allocated to T-bills and what fraction to equity? (Do not round intermediate calculations. Round your answers to 2 decimal places.) T-bills Equity