Definition:Population
Definition
The population of a statistical study is everything in the universe of discourse that is relevant to the study.
It includes all objects, measures, and observations under discussion.
Finite Population
A finite population is a population which is finite.
Infinite Population
An infinite population is a population which is infinite.
Examples
Smokers in London
Consider a random sample of $300$ adult Londoners.
Suppose $75$ of them, that is, $25 \%$ of the random sample, are smokers.
Then $25 \%$ is an appropriate estimate of the proportion of the complete population of adult Londoners who smoke.
Confidence limits may be attached to this estimate.
Thickness of Sheet Metal
Consider measurements of the thickness of $10$ sheets of metal selected at random from the daily production at a factory.
While the actual population which is sampled is only that for a particular day, inferences are often taken to apply to all such sheets that have been or will be produced by the factory.
The assumption made is that the standards of production do not vary appreciably from day to day.
Also known as
The population (of a particular study) can also be referred to as the universe.
See universal set.
Also see
- Results about populations can be found here.
Sources
- 1972: Murray R. Spiegel and R.W. Boxer: Theory and Problems of Statistics (SI ed.) ... (previous) ... (next): Chapter $1$: Variables and Graphs: Population and Sample. Descriptive and Inductive Statistics
- 1989: Ephraim J. Borowski and Jonathan M. Borwein: Dictionary of Mathematics ... (previous) ... (next): population or universe
- 2000: Murray R. Spiegel, John Schiller and R. Alu Srinivasan: Probability and Statistics (2nd ed.): $\S 5$
- 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): population
- 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): population
- 2014: Christopher Clapham and James Nicholson: The Concise Oxford Dictionary of Mathematics (5th ed.) ... (previous) ... (next): population