Use the given decision tree to answer the questions that follow. Payoffs are profits/losses. s1 (0.75) -$1,200 s2 $15,000 st -$3,200 s2 (0.25) $17,700 a) The expected value at node A, EV(A) is $ b) The expected value at node B, EV(B) is $ c) The expected value at node C, EV(C') is $ d) The expected value with perfect information, EV withPI is $ e) The expected value of perfect information, EVPI is $