A statistical average does not till as about the scatterdness or dispersal from it. Thus only or the basis of statically averages, the analysis and interpretation of statistical facts is wrong and erroneous.

The terms dispersion refers to the variability in the size of items. It Indicates that the size of items in a series in not uniform. The values of various items differ from each other.

Methods of measuring Dispersion:-

There are two mathematical methods of ascertaining dispersion :
(A) Methods of limits (B) Methods of moments
(a) Range (a) Mean deviation
(b) Inter-Quantile Rang  (b) Standard Deviation
(c) Percentile Range (c) Other Measures
(d) Quantile Deviation

a- Range :- Higher value (H) “ lowest value(L)

Coefficient of Range

b- Inter quantile Range

c- Percentile Range
d- Semi Inter quantile Range

e- Mean Deviation
From mean

f- From Medium
g- from Mode

h- Standard deviation:-
Coefficient of standard deviations

Author – Dr Archana Dusad