You've observed the following returns on Crash-n-Burn Computer's stock over the past five years: 3 percent. -15 percent, 25 percent, 15 percent, and 15 percent. What was the arithmetic average return on the company's stock over this five-year period? 8.60% 10.75% 10.23% 9.37% 6.97% What was the variance of the company's returns over this period? 0.02348 0.02406 0.01878 0.02137 0.01902 What was the standard deviation of the company's returns over this period? 15.32% 15.51%