Average Deviation

The average deviation is the average of the difference between the absolute values of data points and the mean.

Population Mean Deviation (MD)

$image\popmd.png$

Sample Mean Deviation (MD)

$image\sammd.png$

where

$image\u.png$	= Population Mean
$image\mean.png$	= Sample Mean
N	= number of data values (for a population)
n	= number of data values (for a sample)
xi	= ith data value

See Also