What is correlation in probability?

Updated May 17, 2026

Short answer

Correlation measures the strength and direction of linear relationship between variables.

Deep explanation

Correlation is standardized covariance: ρ = Cov(X,Y)/(σXσY). It ranges from -1 to +1 and indicates linear dependency strength.

Real-world example

Correlation between study time and exam scores.

Common mistakes

  • Assuming correlation implies causation.

Follow-up questions

  • Does correlation imply causation?
  • What is nonlinear correlation?

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