P8-11 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 0.90 . 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 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