Compute the expected payoff, variance, and the standard deviation for each of the following probability distributions:
a. A payoff of 200 with a probability of 0.4 and 500 with a probability of 0.6.
b. A payoff is 110 with a probability of 0.2; 130 with a probability of 0.3; 150 with a probability of 0.1; and 170 with a probability of 0.4.
c. Every possible payoff that's a whole number between (and including) 100 and 200, each with the same probability.