Probability

Discrete Random Variable Table

Build a full PMF table and compute E(X), E(X²), Var(X), SD(X), and the CDF P(X ≤ x) for any discrete random variable. Enter x, P(x) pairs one per line.

Live Calculator · Step-by-Step · Probability
Inputs
Result
Result
Enter values and calculate.

Step-by-Step Work

Your explanation will appear here.

PMF Bar Chart
CDF Step Function P(X ≤ x)
Put It Into Practice

The calculator shows the steps — a quiz proves you can do them on your own.

Stuck on Probability? Get 1-on-1 help

Alexander tutors all math and CS levels — $55/session, free consultation.