Quartile
Quartile
Quartile (/ˈkwɔːr.taɪl/), from the Latin quartus meaning fourth, is a statistical term describing a three-point measure that divides a data set into four equal groups, each group comprising a quarter of the data.
Definition
A quartile is a type of quantile which divides the number of data points into four more or less equal parts, or quarters. The first quartile (Q1) is defined as the middle number between the smallest number and the median of the data set. The second quartile (Q2) is the median of the data. The third quartile (Q3) is the middle value between the median and the highest value of the data set.
Calculation
There are several methods for calculating quartiles. One common method is the "Tukey Method", also known as the "inclusive method". This method includes the following steps:
- Arrange the data in increasing order.
- Find the median (Q2).
- Find the first quartile (Q1), which is the median of the lower half of the data.
- Find the third quartile (Q3), which is the median of the upper half of the data.
Another method is the "exclusive method" which excludes the median when calculating Q1 and Q3 if the data set has an odd number of observations.
Usage
Quartiles are used in descriptive statistics to provide a comprehensive view of the distribution of a data set, along with other statistics such as the mean, median, and mode. They are also used in box plots, a type of graph used to display the distribution of data.
Related Terms
External links
- Medical encyclopedia article on Quartile
- Wikipedia's article - Quartile
This WikiMD dictionary article is a stub. You can help make it a full article.
Languages: - East Asian
中文,
日本,
한국어,
South Asian
हिन्दी,
Urdu,
বাংলা,
తెలుగు,
தமிழ்,
ಕನ್ನಡ,
Southeast Asian
Indonesian,
Vietnamese,
Thai,
မြန်မာဘာသာ,
European
español,
Deutsch,
français,
русский,
português do Brasil,
Italian,
polski