Use the following Cost decision tree and calculate the EV at node $2$ given the EV at node $3=150,$ EV at node $4=178.$

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

P$($s$2)=0\mathrm{.}25$ P$($U$)=0\mathrm{.}2$