Suppose we have the following returns for large$-$company stocks and Treasury bills over a six$-$year period:

$\backslash$table$[[$Year$,$Large$-$Company,US Treasury Bill$],[1,3\mathrm{.}91,5\mathrm{.}87],[2,14\mathrm{.}35,2\mathrm{.}51],[3,19\mathrm{.}29,3\mathrm{.}74],[4,-14\mathrm{.}39,7\mathrm{.}15],[5,-31\mathrm{.}88,5\mathrm{.}34],[6,37\mathrm{.}00,5\mathrm{.}39]]$

a$.$ Calculate the arithmetic average returns for large$-$company stocks and T$-$bills over this time period. $($Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

b$.$ Calculate the standard deviation of the returns for large$-$company stocks and T$-$bills over this time period. $($Do not round intermediate calculations. Enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$

c$-1.$ Calculate the observed risk premium in each year for the large$-$company stocks versus the T$-$bills. What was the arithmetic average risk premium 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$.,32\mathrm{.}16.)$

c$-2.$ Calculate the observed risk premium in each year for the large$-$company stocks versus the T$-$bills. What was the standard deviation of the risk premium over this period? $($Do not round intermediate calculations. Enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$