You$$ve observed the following returns on Crash$-$n$-$Burn Computer$$s stock over the past five years: $5$ percent, $9$ percent, $27$ percent, $21$ percent, and $15$ percent.

What was the arithmetic average return on the company's stock over this five$-$year period?

What was the variance of the company's returns over this period?

What was the standard deviation of the company$$s returns over this period?