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. \begin{tabular}{lcccc} Year & 1 & 2 & 3 & 4 \\ \hline Return & 3.5% & +28.4% & +11.5% & +3.8% \\ \hline \end{tabular}