In the following profit payoff table for a decision problem with two states of nature and three decision alternatives, the probabilities for s1 and s2 are: p(s1)=0.8 and p (s2)= 0.2 State of Nature Decision Alternatives s1 s2 d1 15 10 d2 10 12 d3 8 20 a. What is the optimal decision? b. Find the EVPI