If the economy booms, Meyer\&Company stock will have a return of 20.4 percent. If the economy goes into a recession, the stock will have a loss of 12.7 percent. The probability of a boom is 67 percent while the probability of a recession is 33 percent. What is the standard deviation of the returns on the stock? 11.95% 10.96% 1556% 8.72% 12.87%