The question asks to state the expression for the mean deviation for a grouped quantitative distribution.

1. Problem Description

The question asks to state the expression for the mean deviation for a grouped quantitative distribution.

2. Solution Steps

The mean deviation for a grouped quantitative distribution is given by the formula:

$MD = \frac{\sum f_i |x_i - \bar{x}|}{\sum f_i}$

Where:

$MD$ = Mean Deviation

$f_i$ = Frequency of the i-th group

$x_i$ = Midpoint of the i-th group

$\bar{x}$ = Mean of the grouped data

$\bar{x} = \frac{\sum f_i x_i}{\sum f_i}$

3. Final Answer

$MD = \frac{\sum f_i |x_i - \bar{x}|}{\sum f_i}$