What is a statistic?

A statistic is a number computed from a sample. Contrast this with the definition of a parameter. If a statistic is computed from a random sample (as is typically the case), then it has random variation or sampling error. An example of a statistic would be:

• the average length of stay in the birth hospital for a random sample of 387 infants born in Johnson County, Kansas.

This webpage was written by Steve Simon on 2002-10-11, edited by Steve Simon, and was last modified on 2008-07-08. This page needs minor revisions. Category: Definitions, Category: Hypothesis testing.