Please calculate the standard deviation of each portfolio.

STD=[prob(R1)(R1ER)2+prob(R2)(R2ER)2++prob(Rn)(RnER)2]1/2 \begin{tabular}{|l|l|l|l|l|l|} \hline \multicolumn{2}{|c|}{ Stocks } & \multicolumn{2}{c|}{ Bonds } & \multicolumn{2}{c|}{ Commodities } \\ \hline Probability & Return & Probability & Return & Probability & Return \\ \hline 0.25 & 12% & 0.6 & 10% & 0.2 & 20% \\ \hline 0.25 & 10% & 0.4 & 7.50% & 0.25 & 12% \\ \hline 0.25 & 8% & & & 0.25 & 6% \\ \hline 0.25 & 6% & & & 0.25 & 4% \\ \hline & & & & 0.05 & 0% \\ \hline \end{tabular}