Question

Difference between mean deviation and standard deviation . which is better measure of dispersion and why

Answer 1

Difference between mean deviation and standard deviation.
==================================☆

✴Mean deviation. (MD).
----------------------------------

It is the measures of Central tendency, giving us rough data about the points where data is centered. It is of two types.

Mean deviation about the mean--》

Arithmetic mean of the numerical deviation of the observation from the mean of the data is called the mean deviation about the mean.

(formula is in picture )


Mean deviation about the median.--》

The Arithmetic mean of the numerical deviation of the observation from the median of the data is called the mean deviation about the median.

(formula is in picture)


✴Standard deviation
-------------------------------

the positive square root of the variance is called standard deviation and it is denoted by Sigma.
(Formula is in pic)

Variance--

Mean of the squares of the deviations from the mean is called the variance to be denoted by Sigma square.

(Formula is in pic)