Suppose we have the following returns for large-company stocks and Treasury bills over a six year period: Large Company 3.91 14.35 19.29 -14.39 -31.88 37.00 US Treasury Bill 5.87 2.51 3.74 7.15 5.34 5.39 Year 4 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 decimal places, e.g., 32.16.) Average returns Large company stocks T-bills 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