You've observed the following returns on Yamauchi Corporation's stock over the past five years: -25.5 percent, 14 percent, 31 percent, 2.5 percent, and 21.5 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 rod intermediate calculations and round your answer to 6 decimal -es, e.g., 34.161616.) c. What was the standard deviation of the returns Ove 5 period? (Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16.) a. Arithmetic average return % b. Variance C. Standard deviation %