Consider the following table for a period of six years: 11 Year 1 2 3 4 5 6 Returns Large- U.S. Company Treasury Bills Stocks - 14.99% 7.35% -26.56 8.02 37.29 5.93 23.99 5.37 7.28 5.48 6.63 7.73 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 T-bills % % a-1. Arithmetic average return a-2. Standard deviation %