4. The last four years of returns for a stock are as follows: 3. Year - 4.0% 28.0% 12.0% 4.0% Return a. What is the average annual return? b. What is the variance of the stock's returns? c. What is the standard deviation of the stock's returns? a. What is the average annual return? The average return is %. (Round to two decimal places.) b. What is the variance of the stock's returns? The variance of the returns is (Round to five decimal places.) c. What is the standard deviation of the stock's returns? The standard deviation is %. (Round to two decimal places.)