Advantages of Standard  deviation

a.Standard  deviation is based on all the observations and is rigidly  defined.

b.It is  amenable to algebraic  treatment  and possesses many mathematical properties.

c.It is possible to calculate the combine standard deviation  of two more  group. This is not  possible with any  other  measure.

d.It is less affected by  fluctuations of sampling  than most other measures  of dispersion.

e.For  comparing  variability of two  or more  series coefficient  of variation is considered as most  appropriate and this  is based on S. D mean.