Youve observed the following returns on Mary Ann Data Corporations stock over the past five years: 38.00 percent, 20.00 percent, 23.00 percent, 25.00 percent, and 12.00 percent.

a. What was the arithmetic average return on Mary Anns stock over this five-year period?

b-1. What was the variance of Mary Anns returns over this period? What was the standard deviation?