ExplanationThe mean deviation from the median calculates the arithmetic average of the deviations of the observed values from median of the observed values.The mean deviation is minimum when the deviation is taken from median as the median is the middlemost value of the series and disperse the whole series into minimal value? The mean deviation from the average A is minimum if A represents Median Mean deviation = 1/n(?x - M)M = Median or mean x = values of the observationsCoefficient of mean deviation = Mean deviation/(Mean or median or mode)The mean deviation about median is minimumThe absolute mean deviation about the mean is independent of change of origin.