Britannica
Sources used in this answer
How are quartiles related to the 25th 50th and 75th percentiles?
Created from Britannica articles
using AI.
AI can make mistakes, so verify using Britannica articles.
probability and statistics
Swiss commemorative stamp of mathematician Jakob Bernoulli, issued 1994, displaying the formula and the graph for the law of large numbers, first proved by Bernoulli in 1713.
In statistics, quartiles and percentiles are both methods used to divide a dataset to understand the distribution of values. While percentiles divide an ordered dataset into 100 equal parts, quartiles divide the data into four equal quarters.1
The relationship between these two measures is defined as follows:
- First Quartile (Q1): Corresponds to the 25th percentile, representing the value below which 25 percent of the data points fall.1
- Second Quartile (Q2): Corresponds to the 50th percentile, also known as the median. This is the central value of the dataset, where half of the data points fall below it.1
- Third Quartile (Q3): Corresponds to the 75th percentile, representing the value below which 75 percent of the data points fall.1
Together with the minimum and maximum values, these three quartiles form a "five-number summary," which is a standard tool used in data analysis to describe the spread and central tendency of a distribution.1