Quartile

Quartile

Each of the three values that divide an ordered statistical series into four parts with equal frequencies.

Notation

The three quartiles that divide a distribution of statistical data are noted as $$\textrm{Q}_1$$, $$\textrm{Q}_2$$ and $$\textrm{Q}_3$$, where $$\textrm{Q}_2$$ is also the median of the distribution.