You've observed the following returns on SkyNet Data Corporation's stock over the past five years: 19 percent, -13 percent, 16 percent, 21 percent, and 10 percent. a. What was the arithmetic average return on the 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- What was the variance of the stock's returns over this period? (Do not round 1. intermediate calculations and round your answer to 5 decimal places, e.g., 32.16161.) b- What was the standard deviation of the stock's returns over this period? (Do not 2. round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.)