After studying the economy, you forecast that there is a 70% chance of a good economy next year and a 30% chance of a poor economy. If the economy is good, you estimate that a stock you have been following would have a 15% return. Likewise, if the economy is poor, you estimate a -10% return for that same stock. The risk-free rate is 4.3%. What is the standard deviation of the expected returns for this stock? (Answer to the nearest tenth of a percent, but do not use a percent sign).

Probability

Return

Good Economy

70%

15%

Poor Economy

30%

-10%

Risk-Free Rate = 4.3