Important: The stats package has been deprecated. Use the superseding package Statistics instead.

The function meandeviation of the subpackage stats[describe, ...] computes the  mean deviation of the given data.

The mean deviation is defined as follows:  the mean is first removed from the data, then the absolute value is taken for each item. The mean deviation is the mean  of the resulting list.

The mean deviation is a measure of the dispersion of the data. For more information about such measures, refer to describe[standarddeviation].

When the arithmetic mean is not a suitable measure of the central tendency of the data, then neither is the mean deviation a suitable measure of the dispersion of the data. For more information please refer to the various measures of central tendency, such as describe[mean].

Classes are assumed to be represented by the class mark, for example 10..12 has the value 11. Missing data are ignored.

The command with(stats[describe],meandeviation) allows the use of the abbreviated form of this command.

$\mathrm{with}\left(\mathrm{stats}\right)\:$

$\mathrm{describe}\left[\mathrm{meandeviation}\right]\left(\left[1\,3\,7\right]\right),\mathrm{describe}\left[\mathrm{meandeviation}\right]\left(\left[2\,3\,5\right]\right)$

$\frac{20}{9},\frac{10}{9}$

$\mathrm{describe}\left[\mathrm{meandeviation}\right]\left(\left[\mathrm{Weight}\left(1\,100\right)\,\mathrm{Weight}\left(100000\,1\right)\right]\right)$

$\frac{19999800}{10201}$

$\mathrm{evalf}\left(\right)$

$1960.572493$