Method of Calculation of Mean  Deviation

a.Computation of Mean Deviation Individual Series : The process of computing mean  deviation in case  of individual series involves  the followings steps.

a.Calculate the  average mean  median  mo mode  of the  series.

b.Take  the deviations  of items  from average   ignoring  +  and  -  sings and denote  these  deviations by  | d| .

c.Compute the total  of these  deviation i, e, ∑ |d|

d.Divide this total  obtained by the number  of items.

Symbolically

Mean Deviation = ∑|d|/ n

Where |d| =  deviation from mean ( or  median) ignoring+ sings

N =  number  of items.