# Statistic

## Single measure of some attribute of a sample / From Wikipedia, the free encyclopedia

#### Dear Wikiwand AI, let's keep it short by simply answering these key questions:

Can you list the top facts and stats about Statistic?

Summarize this article for a 10 year old

A **statistic** (singular) or **sample statistic** is any quantity computed from values in a sample which is considered for a statistical purpose. Statistical purposes include estimating a population parameter, describing a sample, or evaluating a hypothesis. The average (or mean) of sample values is a statistic. The term statistic is used both for the function and for the value of the function on a given sample. When a statistic is being used for a specific purpose, it may be referred to by a name indicating its purpose.

When a statistic is used for estimating a population parameter, the statistic is called an *estimator*. A population parameter is any characteristic of a population under study, but when it is not feasible to directly measure the value of a population parameter, statistical methods are used to infer the likely value of the parameter on the basis of a statistic computed from a sample taken from the population. For example, the sample mean is an unbiased estimator of the population mean. This means that the expected value of the sample mean equals the true population mean.^{[1]}

A *descriptive statistic* is used to summarize the sample data. A *test statistic* is used in statistical hypothesis testing. A single statistic can be used for multiple purposes ā for example, the sample mean can be used to estimate the population mean, to describe a sample data set, or to test a hypothesis.