Suppose we have the following returns for large-company stocks and Treasury bills over a six-year period: {:[{:[10],[" polnts "]:}," Year ",{:[" Large- "],[" Company "],[" stocks "]:},{:[" US Treasury "],[" bills "]:}],[" eBook ",1,3.91%,5.87%],[" Hint ",2,14.35,2.51],[,3,19.29,3.74],[" Print ",4,-14.39,7.15],[" References ",5,-31.88,5.34],[,6,37.00,5.39]:} a. Calculate the arithmetic average returns for large-company stocks and T-bills over this period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) b. Calculate the standard deviation of the returns for large-company stocks and T-bills over this period. (Do not round intermediate calculations and enter your answers as a percent rounded