a. You've observed the following returns on Crash-n-Burn Computer's stock over the past five years: 15 percent, -6 percent, 18 percent, 14 percent, and 10 percent. What was the arithmetic average return on the company's stock over this five-year period? (Do not round intermediate calculations and enter your answer as a percent rounded to 1 decimal place, e.g., 32.1.) b-1. What was the variance of the company's returns over this period? (Do not round intermediate calculations and round your answer to 5 decimal places, e.g., .16161.) b-2. What was the standard deviation of the company's returns over this period? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)