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.