Discussion:
Q: Let x be a random variable with the following probability distribution:
Value x of X......P(X = x)
........-1...............0.05
.........0...............0.05
.........1...............0.60
.........2...............0.05
.........3...............0.15
.........4...............0.10
Find the expectation E(X) and variance var(X) of X.