What is the expected value of perfect information with demans of 50% 20% and 30% what are the expected annual profits?

\begin{tabular}{lccc} & \multicolumn{2}{c}{ Demand } \\ \# of Assistants & low & medium & high \\ One & 620 & 100 & 620 \\ Two & 300 & 250 & 555 \\ Three & 0 & 0 & 615 \end{tabular}