Just as a frequency distribution associates variable values to corresponding frequencies, a probability distribution associates the outcomes of a random experiment to corresponding probabilities.
Discrete Probability Distribution Definition
An association of the outcomes of a discrete probability distribution with corresponding probabilities if the following two conditions are satisfied.
- The sum of all the probabilities in the sample space = 1; that is ∑P(X) = 1
- The probability of each event must be between 0 and 1. that is 0 ≤ P(X) ≤ 1.
The expectation of a discrete distribution E(X) = Mean μ = ∑X.P(X)
The variance of the discrete distribution X, σ2 = [E(x)]2- μ2.
Let us look at some of the discrete distributions.