Using the following Profit decision tree, Calculate EVSI knowing EV at node $2$ equals $165$ and EV at node $5$ equals $178.$

P$($s$1)=0\mathrm{.}75$ P$($F$)=0\mathrm{.}8$ P$($s$1|$F$)=0\mathrm{.}85$ P$($s$1|$U$)=0\mathrm{.}55$

P$($s$2)=0\mathrm{.}25$ P$($U$)=0\mathrm{.}2$ P$($s $2|$F$)=0\mathrm{.}15$ P$($s$2|$U$)=0\mathrm{.}45$