The mean absolute deviation for ungrouped data
Let $x_i, i=1,2, \cdots , n$ be $n$ observations.
The mean of $X$ is denoted by $\overline{x}$ and is given by
$$ \begin{eqnarray*} \overline{x}& =\frac{1}{n}\sum_{i=1}^{n}x_i \end{eqnarray*} $$
Formula:
$MAD =\dfrac{1}{n}\sum_{i=1}^{n}|x_i -\overline{x}|$
where,
$n$total number of observations$\overline{x}$sample mean