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 [latex]\textrm{Q}_1[/latex], [latex]\textrm{Q}_2[/latex] and [latex]\textrm{Q}_3[/latex], where [latex]\textrm{Q}_2[/latex] is also the median of the distribution.
