After extensive research, you believe the probability distribution for next year's return on FB Inc is:
Return Probability
10.5% 0.2
3.2% 0.3
-5.2% 0.3
12.1% 0.2
Compute the standard deviation of this return.
Express your answer as a percentage to three decimal places (the percent sign is not essential). That is, if you compute a standard deviation of 0.12345, enter your answer as 12.345.