You've observed the following returns on Pine Computer's stock over the past five years: -28.8 percent, 16.2 percent, 35.4 percent, 3.6 percent, and 22.6 percent. a. What was the arithmetic average return on the stock over this five-year period? Note: Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16 . b. What was the variance of the returns over this period? Note: Do not round intermediate calculations and round your answer to 6 decimal places, e.g., .161616 . c. What was the standard deviation of the returns over this period? Note: Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16