Hi. Can anyone please help with this? No one has gotten it correct yet. Thank you!

You've observed the following returns on Doyscher Corporation's stock over the past five years: -26.7 percent, 14.8 percent, 32.6 percent, 2.9 percent, and 21.9 percent. Requirement 1: What was the arithmetic average return on the stock over this five-year period? Arithmetic average return 9.1 % Requirement 2: (a) What was the variance of the returns over this period? Variance (b)What was the standard deviation of the returns over this period? Standard deviation %