---
tag: 0P4FTHHMYS
kind: concept
name: Standard deviation
msc: [60A05]
sources:
  - url: https://en.wikipedia.org/wiki/Standard_deviation
    locator: lead section
same_as:
  wikidata: Q159375
  wikipedia: Standard deviation
---

## Summary

The standard deviation of a random variable is the square root of its variance. It measures the spread of the values in the same units as the variable.
The node [[standard deviation|0VTN5RKNC5]] gives the precise definition.