What is joint probability?

Updated May 17, 2026

Short answer

Joint probability is the probability of two events occurring together.

Deep explanation

Joint probability P(A ∩ B) measures the likelihood that both events A and B happen simultaneously. It is fundamental for understanding dependence and conditional probability.

Real-world example

Probability that it rains and there is traffic congestion.

Common mistakes

  • Assuming joint probability equals product without checking independence.

Follow-up questions

  • How is joint probability related to conditional probability?
  • What is joint distribution?

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