After some study of the economy, your forecast for next year is that a boom economy has a 30% chance of occurring, a neutral economy 50%, and a bust economy a 20% chance of occurring. You also estimate that a certain stock would have a return of 35% in a boom economy next year, 16% in a neutral economy , and -11% in a bust economy. The risk-free rate is 4.8%. What is the standard deviation of expected returns for this stock next year? (Answer to the nearest tenth of a percent, but do not use a percent sign).
Probability Return
30% 35%
50% 16%
20% -11%
Risk-Free Rate = 4.8%