he last four years of returns for a stock are as$$ follows:

Year

$1$

$2$

$3$

$4$

Return

$\%$

$\%$

$\%$

$\%$

a$.$ What is the average annual$$ return?

b$.$ What is the variance of the$$ stock's returns?

c$.$ What is the standard deviation of the$$ stock's returns?