---
tag: 0A9EB0KQBC
kind: concept
name: Chi-squared distribution
aliases: [chi-square-distribution, chi-squared]
msc: ["60E05", "62E15"]
sources:
  - url: https://en.wikipedia.org/wiki/Chi-squared_distribution
    locator: lead section
same_as:
  wikidata: Q243462
  wikipedia: Chi-squared distribution
---

## Summary

The chi-squared distribution with $k$ degrees of freedom is the law of a sum of the squares of $k$ independent standard normal random variables. It is central in tests and confidence intervals for variances.
The node [[chi-squared distribution|0RFMMBHFTV]] gives the precise definition.