The last four years of returns for a stock are as follows: 1 2 4 3 +12.5% -3.5% +28.5% +4.5% (a) What is the average annual return? %. (Round to two decimal places.) (b) What is the variance of the stock's returns? (Round to five decimal places.) (c) What is the standard deviation of the stock's returns? %. (Round to two decimal places.) Check