You've observed the following returns on Pine Computer's stock over the past five years: $-25\mathrm{.}5$ percent, $14$ percent, $31$ percent, $2\mathrm{.}5$ percent, and $21\mathrm{.}5$ percent.

a$.$ What was the arithmetic average return on the stock over this five$-$year period?

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

b$.$ What was the variance of the returns over this period?

Note: Do not round intermediate calculations and round your answer to $6$ decimal places, e$.$g$.,.161616.$

c$.$ What was the standard deviation of the returns over this period?

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

$\backslash$table$[[$a$.$ Arithmetic average return,$8\mathrm{.}70,\%$