Calculating Returns and Standard Deviations Based on the following information, calculate the expected returns and standard deviations for the two stocks.

$\backslash$table$[[\backslash$table$[[$State of$],[$Economy$]],\backslash$table$[[$Probability of$],[$State of Economy$]],$Rate of Return if State Occurs$],[$Stock A$,$Stock B$],[$Recession$,10,\mathrm{.}02,-\mathrm{.}30],[\backslash$table$[[$Normal$],[$Boom$]],\mathrm{.}50,\backslash$table$[[\mathrm{.}10],[15]],18],[$Boom$,,\mathrm{.}15,\mathrm{.}31]]$