US Treasury Bill 3.99 14.16 19.25 -14.43 -31.92 37.49 4.59 4.94 3.86 6.99 5.30 6.20 3 5 a. Calculate the arithmetic average returns for large-company stocks and T -bills over this period. (Do not round intermediate calculations. Enter your answers as a percent rounded to 2 0-g., 32.16) Average returns Large company stocks T-bills 4.76 % 5.31 % b. Calculate the standard deviation of the returns for large-company stocks and T-bills over this period. (Do not round intermediate calculations. Enter your answers as a percent rounded to 2 decimal places, e.g, 32.16.) Standard deviation Large company stocks T-bills