Consider the following table for a period of six years: Year Returns Large-Company Stocks U.S. Treasury Bills 1 -15.09% 7.37% 2 -26.59 8.03 3 37.31 5.95 4 24.01 5.47 5 -7.32 5.49 6 6.65 7.76 a-1. Calculate the arithmetic average returns for large-company stocks and T-bills over this time period. Note: 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. Note: 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 %