need to figure out how to hand-write the problem out, cannot use excel

You've observed the following returns on Pine Computer's stock over the past five years: -26.7 percent, 14.8 percent, 32.6 percent, 2.9 percent, and 21.9 percent. a. What was the arithmetic average return on the stock over this five-year period? Note: 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? Note: 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? Note: Do not round intermediate calculations and enter your answer as a percent rounded to 2 decimal places, e.g., 32.16