A stock will have a loss of 13.3 percent in a recession, a return of 12 percent in a normal economy, and a return of 26.7 percent in a boom. There is 30 percent probability of a recession, 39 percent probability of normal economy, and 31 percent probability of boom. What is the standard deviation of the stock's returns? 13.55% 1185 14.49% 15 315