P12-9 Calculating Returns and Variability (LO1] You've observed the following returns on Crash-n-Burn Computer's stock over the past five years: 5 percent, -10 percent, 28 percent, 16 percent, and 17 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