What is a Random Variable?

Probability · Axiom Academy

INTRO What is a Random Variable? Discover how we turn random outcomes into numbers we can work with. Click on any die face below. Each represents a possible outcome when you roll a die. Click the button below to flip three coins. Watch how we count the number of heads. Click the button to see different random experiments and their random variables. A function that assigns a numerical value to each outcome of a random experiment. We denote it with capital letters like X, Y, or Z. • X = number on a die roll • X = number of heads in 3 coin flips • X = number of customers arriving in an hour Random variables transform unpredictable outcomes into numbers we can analyze with mathematical tools like probability distributions, expected values, and variance.

This is the written version of the interactive lesson above. See the full Probability course.