8. Discrete Probability Distributions

A numerical variable whose value depends on the outcome of a chance or random event is called a random variable. If the set of possible values of a random variable is countable or finite, it is called a discrete random variable.

A discrete probability distribution function has two characteristics:

Each probability is between zero and one, inclusive.
The sum of the probabilities is one.

Adapted from Python for Introductory Statistics, by Simon Aman (Truman College, City Colleges of Chicago), licensed under CC BY 4.0. Changes were made: reformatted as an accessible XYZ web edition with live in-browser code cells. License: CC-BY-4.0.