In common language the word ‘Population’ means the number of personal living in a certain region. We may find the population of certain animals in forests in a country or the population of certain plants in a garden and so on the term population implies ‘ head count ’.
However, in statistics, the data on any single variable, or a set of variables, for all individual units in a region, constitute the population of that variable, or variables.
1. Univariate:
If the data are on a single variable, the set of measurements constitutes a univariate population of that variable. We have a bivariate or multivariate population of the set variables. For example, we may have a univariate population of prices or a population of incomes, We may have a bivariate population of height and weights of all individuals in a region.
2. Multivariate:
A multivariate population of expenditure on various items of consumption of all households.
