You've observed the following returns on Yamauchi Corporation's stock over the past five years: -10 percent, 24 percent, 21 percent, 11 percent, and 8 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 2 decimal places, e.g., 32.16.) b. What was the variance of the returns over this period? (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? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) Arithmetic average return . b. Variance Standard deviation %