Population mean

A measure of the centre for a population distribution of a numerical variable. The population mean is the mean of all values of a numerical variable based on the collection of all objects or individuals of interest. It is the centre of mass of the values in a population distribution.

If the collection is finite, then the population mean is obtained by adding all values in a set of values and then dividing this total by the number of values.

In many real-life situations, the entire collection of values from a population is not available for a variety of reasons. For example, the collection may be infinite, or some objects or individuals may not be accessible. In such cases, the value of the population mean is not known. The population mean may be estimated by taking a random sample of values from the population, calculating the sample mean, and using this value as an estimate of the population mean.

The population mean is a number representing the centre of the population distribution and is therefore an example of a population parameter.

The Greek letter µ (mu) is the most common symbol for the population mean.

See: expected value (of a discrete random variable), mean, measure of centre

Curriculum achievement objectives references

Statistical investigation: Levels 6, 7, 8

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