Reviewed by Oct 05, 2020| Updated on
A quintile refers to a data value in statistics. In a data set, quintile represents 20% of the population. The first quintile is representative of the lowest one-fifth of the data set (1- 20%). The second quintile is representative of the second-fifth (21% to 40%) and similarly the others. Quintiles help in creating different cut-off points in a data set or population.
A quintile essentially is a type of quantile which consists of uniform-sized segments of a given population. The median, which is a statistical tool for data analysis derives its value by the division of the population in two quantiles. Similarly, quintile is also a type of quantile but divides the data into five uniform parts.
Each quintile is one of five portions from the division of data into five equal parts. Each part is 20% of the entire range of the population. In a case where the population is split into three equal parts, each part is a tertile. And, in the case of four equal parts, each part is a quartile. Normally, large data sets are divided into different quantiles for statistical analysis.
From a practical perspective, economists use statistical tools, such as quintiles to understand and study data sets. Examples of data study can be the population of a country or a study of demographics and economic status of the population. Many a time, the government carries out the study to enable implementation of welfare schemes.
In other cases, quintiles find use in analysing movements in prices of stocks or commodities in financial markets. The top 20% represents the uppermost quintile of the data set. The bottom 20% represents the lowermost quintile of the data set. In the analysis, one can find the average price between the second and fourth quintile.
The government of a State or an organisation may use various statistical tools to understand the population before implementing any scheme. The government uses quintiles, tertiles, or quartiles to break the data into different segments. The study helps the government in framing suitable social and economic schemes for development or taxation policies.