You've observed the following returns on Mary Ann Data Corporation's stock over the past five years: 13 percent, 8 percent, 16 percent, 16 percent, and 10 percent. a. What was the arithmetic average return on Mary Ann's stock over this five-year period? (Do not round intermediate calculations and round your final answer to 2 decimal places. (e.g., 32.16)) b. What was the variance of Mary Ann'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 Mary Ann's returns over this period? (Do not 2. round intermediate calculations and round your final answer to 2 decimal places. (e.9.,32.16))