Suppose we have the following returns for large-company stocks and Treasury bills over a six-year period: Year Large- Company US Treasury bills stocks 1 13 3.99% 6.65% 23456 14.50 4.46 19.39 4.33 -14.29 7.34 5.44 6.45 S a. -31.78 37.10 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.) 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.) c-1. Calculate the observed risk premium in each year for the large-company stocks versus the T-bills. What was the average risk premium over this period? (A negative answer should be indicated by a minus sign. Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) c-2. Calculate the observed risk premium in each year for the large-company stocks versus the T-bills. What was the standard deviation of the risk premium over this period? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)