Youve observed the following returns on Crash-n-Burn Computers stock over the past five years: 5 percent, -11 percent, 24 percent, 18 percent, and 17 percent. What was the arithmetic average return on Crash-n-Burns stock over this five year period? What was the variance of Crash-n-Burns returns over this period? What was the standard deviation of Crash-n-Burns returns over this period?