Consider the following rates of return:

Year Large$-$Company Stocks U$.$S$.$ Treasury Bills

$114\mathrm{.}69\%6\mathrm{.}93\%$

$226\mathrm{.}478\mathrm{.}00$

$337\mathrm{.}235\mathrm{.}80$

$423\mathrm{.}935\mathrm{.}08$

$57\mathrm{.}165\mathrm{.}12$

$66\mathrm{.}577\mathrm{.}18$

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$.,32\mathrm{.}16.)$

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 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 and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$