The next four questions refer to a problem for which we have three decision alternatives and three states of nature with

[answerhappygod]

The next four questions refer to a problem for which we have
three decision alternatives and three states of nature with the
following payoffs:
s1 s2 s.3
d1 400 500 660
d2 -250 650 800
d3 -400 580 990
Which decision should be made according to the optimistic
approach? Which decision should be made according to the minimax
regret approach? Suppose the following probabilities are given:
P(s1) = 0.2, P(s2) = 0.5, P(s3) = 0.3. Which decision should be
made according to the expected value approach? What is the expected
value of perfect information?