Consider the following table for a period of six years:

Year Returns

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

$116\mathrm{.}09\%7\mathrm{.}57\%$

$226\mathrm{.}898\mathrm{.}13$

$337\mathrm{.}516\mathrm{.}15$

$424\mathrm{.}216\mathrm{.}47$

$57\mathrm{.}725\mathrm{.}59$

$66\mathrm{.}858\mathrm{.}06$

a$-1.$ Calculate the arithmetic average returns for large$-$company stocks and T$-$bills over this time period.

Note: Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

a$-2.$ Calculate the standard deviation of the returns for large$-$company stocks and T$-$bills over this time period.