answer both a and b

Note: You must show your work to get the full credit. 1) You find a certain stock that had returns of 17 percent, -24 percent, 25 percent, and 8 percent for four of the last five years. The average return of the stock over this period was 10.4 percent. a. What was the stock's return for the missing year? b. What is the standard deviation of the stock's returns