Youve observed the following returns on Crash-n-Burn Computers stock over the past five years: 3 percent, -11 percent, 27 percent, 21 percent, and 15 percent. Requirement 1: What was the arithmetic average return on Crash-n-Burns stock over this five year period? Requirement 2: (a) What was the variance of Crash-n-Burns returns over this period? (Do not round intermediate calculations.) (b) What was the standard deviation of Crash-n-Burns returns over this period? (Do not round intermediate calculations.)