Stock A has annual returns (R) of 5.5%, 26.73%, 48.25%, -4.5%, 43.86% for each year during the past five years. What is the average return and sample standard deviation (Sx) for stock A? (Use the Stat function in a calculator, refer the formula sheet occasionally). 23.97%, 23.15% 28.9%, 17% 24.9%, 25% 21.9%, 22%