Problem 10-8 Risk Premiums Consider the following rates of return: US Treasury Bill Large- Year Company Stocks 1 3.98% 2 14.17 3 19.31 4 -14.37 5 -31.86 6 37.02 6.62% 4.44 4.31 7.33 5.36 6.23 a. Calculate the arithmetic average returns for large-company stocks and T-bills over this period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) Large company stocks 4.71% T-bills % b. Calculate the standard deviation of the returns for large-company stocks and T-bills over this period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) Large company stocks % T-bills 1.22 %