suppose we have the following treasury bill returns and inflation rates over an eight-year period: year treasury bills inflation 1 10.45% 12.55% 2 11.36 16.00 3 9.06 10.29 4 8.34 7.97 5 8.88 10.29 6 11.23 12.77 7 14.11 16.98 8 15.97 16.90 a. calculate the average return for treasury bills and the average annual inflation rate 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 answers as a percent rounded to 2 decimal places, e.g., 32.16.) c. what was 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.)