Rate of return, standard deviation, coefficient of variation: mike is searching for a stock to include in his current stock portfolio. he is interested in hi-tech inc.; he has been impressed with the company's computer products and believes hi-tech 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 1.19. mike has obtained the following price information for the period 2015 through 2018: hi-tech stock, being growth-oriented, did not pay any dividends during these 4 years.

stock price
year begin end
2015 $14.35 $20.32
2016 $20.32 $64.78
2017 $64.78 $72.12
2018 $72.12 $90.45

a. calculate the rate of return for each year, 2015 through 2018, for hi-tech stock.
b. assume that each year's return is equally probable and calculate the average return over this time period.
c. calculate the standard deviation of returns over the past 4 years.  (hint: treat this data as a sample.)
d. based on b and c determine the coefficient of variation of returns for the security.
e. given the calculation in d what should be mike's decision regarding the inclusion of hi-tech stock in his portfolio?