You've observed the following returns on Regina Computer's stock over the past five years: $19\%,-13\%,16\%,21\%,$ and $10\%.$

a$.$ What was the arithmetic average return on Regina's stock over this five$-$year period? $($Round the final answer to $1$ decimal place.$)$

Average return

b$-1.$ What was the variance of Regina's returns over this period? $($Do not round intermediate calculations. Round the final answer to

$5$ decimal places.$)$

Variance

b$-2.$ What was the standard deviation of Regina's returns over this period? $($Do not round intermediate calculations. Round the final

answer to $1$ decimal place.$)$

Standard deviation