The following measures of absolute dispersion are in common use :


1) Based on selected items of the data 

i) Range - spread for entire data

ii) Inter Quartile Range - spread for middle 50% data. More commonly Quartile Deviation is used in its place, which is half of inter quartile range.


2) Based on all items of the data

i) Mean Deviation - mean of the absolute deviations from central tendency.

ii) Standard Deviation or Root Mean Square Deviation about arithmetic mean


3) A Graphic Method - Lorenz Curve (This, however, is not a part of discussion in this course).


The relative measures of dispersion corresponding to the measures of absolute dispersion are :



 Absolute Measures of Dispersion

Relative Measures of Dispersion



Coefficient of Range


Quartile Deviation 

Coefficient of Quartile Deviation


Mean Deviation 

Coefficient of Mean Deviation


Standard Deviation

Coefficient of Standard Deviation



Mayank Rai

Hi, My name is Mayank Rai. I found that Blogging is an easiest way to share your knowledge with everyone & learn something new from there.

Post a Comment

Previous Post Next Post