Expected value helps us find average value we can expect from an random event
Formula: E = Σ(x * P(x))
Example:
I roll a fair six-sided dice. What’s the expected value from the dice?
There are six possible outcomes (1, 2, 3, 4, 5, and 6)
Each outcome has an equal probability of occurring (P(x) = 1/6 for all x)
E = Σ(x * P(x))
E = x1 * P(x1) + x2 * P(x2) + x3 * P(x3) + x4 * P(x4) + x5 * P(x5) + x6 * P(x6)
E = (1 * 1/6) + (2 * 1/6) + (3 * 1/6) + (4 * 1/6) + (5 * 1/6) + (6 * 1/6)
E = 3.5
This suggests that over many rolls, the average outcome will be closer to 3.5
