The last four years of returns for a stock are as shown here: 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? Note: Notice that the average return and standard deviation must be entered in percentage format. The variance must be entered in decimal format. Year 2 3 4 1 -4.5% Return - + 28.1% + 12.4% + 4.3%