Exelon Corp believes the following probability distribution exists for its stock. What is the standard deviation of the estimated returns? Round your intermediate calculations to at lease 4 decimal places. PLEASE PROVIDE FORMULA IN EXCEL PLZ

a. 8.5441%

b. 3.1892% c.

c. 0.7300%

d. 17.8582%

\begin{tabular}{|llll|} \hline Stateofthe & ProbabilityofState & StocksExpected \\ Economy & Occurring & & Return \\ \cline { 1 - 1 } Boom & & 0.28 & 35% \\ Normal & & 0.52 & 24% \\ Recession & 0.20 & 10% \\ \hline \end{tabular}