The Firm Has Estimated the Three Different Returns Under Different

Multiple Choice

The firm has estimated the three different returns under different states of economy. The probabilities of each state and the returns are provided in the table below. What is the standard deviation of the firm's returns?
$$\begin{array} { | l | l | l | l | } \hline \text { State of Economy } & \text { Recession } & \text { Normal } & \text { Boom } \\\hline \text { Probability } & 0.2 & 0.7 & 0.1 \\\hline \text { Return } & - 100 & 200 & 500 \\\hline\end{array}$$

A) 161.55
B) 192.09
C) 26100
D) 36900