Use the given decision tree to answer the questions that follow. Payoffs are costs. P(s;) = 0.54 $5,300 $4,700 $4,200 $3,500 a) The expected value at node A, EV(A) = ' 5024 '. b) The expected value at node B, EV(B) = c) The expected value at node C, EV(C) =