Youve observed the following returns on Apple stock over the past five years: 14%, -9%, 16%, 21%, and 3 %. a. What was the (arithmetic) average return on the stock over this five-year period? b. What was the historical variance of the stocks returns over the period? c. What was the standard deviation of the stocks returns over the period? d. What was the risk premium on the stock if the risk-free rate for the period was 4.2 percent?