Consider the following table for a period of six years: Year 123456 Returns Large- U.S. Company Treasury Bills Stocks - 15.19% 7.39% -26.62 8.04 37.33 5.97 24.03 5.57 - 7.36 5.50 6.67 7.79 a-1. Calculate the arithmetic average returns for large-company stocks and T-bills over this time period. (Do not round Intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) a-2. Calculate the standard deviation of the returns for large-company stocks and T-bills over this time 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 a-1. Arithmetic average return a-2. Standard deviation % T-bills % Calculate the observed risk premium in each year for the large-company stocks versus the T-bills. b-1. What was the arithmetic 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.) b-2. 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.) b-1. Average risk premium % b-2. Risk premium standard deviation %