year period: a. Calculate the arithmetic average return for Treasury bills and the average annual inflation rate (consumer price index) for 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 Treasury bill returns and inflation over this period. (Do not round intermediate calculations and enter your ariswers as a percent rounded to 2 decimal places, e.g., 32.16.) b. Calculate the standard deviation of Treasury bill returns and inflation over this period. (Do not round intermediate calculations and enter your answers as a percent rounded to 2 decimal places, e.g., 32.16.) c. What is the average real return for Treasury bills over this period? (A negative answer should be indicated by a minus sign. Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)