Rate of return, standard deviation, and coefficient of variation. Mike is searching for a stock to include in his current stock portfolio. He is interested in

Dell Technologies Inc.; he has been impressed with Dell's computer products and believes that Dell is an innovative market player. However, Mike realizes that

any time you consider a technology stock, risk is a major concern. The rule he follows is to include only securities with a coefficient of variation of returns

below $0\mathrm{.}90.$ Mike has obtained the following price information for Dell stock. Dell has not paid any dividends during these three years.

a$.$ Calculate the rate of return for each year.

b$.$ Calculate the average return over time.

c$.$ Calculate the standard deviation over the past three years.

d$.$ Based on parts $b$ and $c,$ determine the coefficient of variation of returns for the security.

e$.$ Given the calculation in part $d,$ what should be Mike's decision regarding the inclusion of Dell stock in his portfolio?