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 round intermediate calculations and round your answer to 6 decimal places, e. g., 32.161616.) 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.)