Please show work and formulas, don't use excel

You find a certain stock that had returns of 14 percent, -27 percent, 19 percent, and 21 percent for four of the last five years, respectively. (12 points) a. What is the average return of the stock over this period? i. Compute the arithmetic average. ii. Compute the geometric average. b. What is the standard deviation of the stock's returns? . Explain the difference between computing the value of a zero-growth dividend- paying stock and computing the value of a constant growth dividend-paying stock