You$$ve observed the following returns on Pine Computer$$s stock over the past five years: $13$ percent, $13$ percent, $20$ percent, $25$ percent, and $10$ percent.

a$.$

What was the arithmetic average return on the company$$s stock over this five$-$year period? $($Do not round intermediate calculations and enter your answer as a percent rounded to $1$ decimal place, e$.$g$.,32\mathrm{.}1.)$

b$-1.$ What was the variance of the company$$s returns over this period? $($Do not round intermediate calculations and round your answer to $5$ decimal places, e$.$g$.,\mathrm{.}16161.)$

b$-2.$ What was the standard deviation of the company$$s returns over this period? $($Do not round intermediate calculations and enter your answer as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.)$