- What is a statistical population?
- Characteristics of a statistical population
- Types of statistical populations
- Statistical subpopulation
We explain what a statistical population is, its characteristics and what types exist. Also, what is a statistical subpopulation.
What is a statistical population?
A statistical population (or, in an area clearly and openly referred to the world of statistics, simply as population), is the set of elements that are of interest to a experiment, a study or a consideration of some kind. The elements that compose it can be, for example, individuals, animals, phenomena or events.
In fact, all forms of statistical study aspire to provide information on a given population in advance, either real and existing (such as the total number of voters in a country), or hypothetical (such as the total number of times we toss a coin into the air ).
Therefore, the statistical population represents the universe of the elements to be considered, that is, its full totality, and in this it is distinguished from a statistical sample. The latter is a portion of said universe, that is, a subset of the population, which is taken for analysis since it is much smaller and more manageable than the total, but still representative of it.
Statistical samples are studied to obtain conclusions probable with respect to statistical populations whose individual and detailed study would be practically impossible.
For example, if a jar contains 50 coins of five cents and another 50 of ten, the statistical population will be 100 coins, since when reaching in and taking a sample, there will be that total number of elements, among which take a handful .
Characteristics of a statistical population
A statistical population is characterized by the following:
- It constitutes a total of elements of statistical interest for some reason, from which representative samples can be taken.
- It can be more or less uniform or heterogeneous, and in the same way it can be made up of real or imaginary elements, finite or virtually unlimited.
- It should not be confused with a statistical sample.
Types of statistical populations
Statistical populations are classified into two, according to their finiteness:
- Finite statistical population. As its name indicates, it is made up of a limited and encompassing amount of elements, which at a given moment in time is equivalent to a specific number. For example: the number of cars in circulation in a city on a Monday morning.
- Infinite statistical population. On the other hand, these types of statistical populations have a virtually unlimited number of elements, that is, they do not have a specific purpose at any given time, either because they really are unlimited, or because their number is so large that we could never know for sure. . For example: the number of sodium atoms in the universe.
Statistical subpopulation
A statistical subpopulation is a portion of the statistical population that can be considered a universe in itself, since its members share an exclusive trait with respect to the rest. That is, a statistical subpopulation is a population within the population, which is generated by adding specific traits to the selection criteria.
For example: in the universe of current European citizens, it is possible to choose different subpopulations according to their particular nationality: Italian, French, Spanish, German, etc. Within each of these sub-populations, it is possible to do the same again if we consider the sub-populations of German males and German females, for example.