\begin{block}{Interquartile range}
Assume that we have $n$ measurements, $x_1, x_2, ... x_n$ and let $Q_1$ denote the first quartile and $Q_3$ denote the third quartile. The \textbf{Interquartile range} of the measurements is denoted with $IQR$ and calculated with
\begin{equation*}
IQR = Q_3 - Q_1.
\end{equation*}
\end{block}