Mean Deviation about Median for Discrete Frequency Distributions

Q.

Calculate the mean deviation about median for the following data

$\begin{array}{cccccc}{X}_i& 3& 9& 10& 12& 13\\ f_i& 3& 4& 5& 2& 4\end{array}$

1. 2.21

2. 2.27

3. 2.56

4. 2.43

Q.

Calculate mean deviation about median for following readings
$\begin{array}{ccccc}Class& 20-40& 40-60& 60-80& 80-100\\ F_i& 20& 44& 30& 40\end{array}$

1. 18.6

2. 18.7

3. 18.8

4. 18.9

Q. $d_i$ is the deviation of a class mark $y_i$ from ‘a’ the assumed mean and $f_i$ is the frequency, if $M_g=x+\frac{1}{\sum f_i}(\sum f_i{d}_i)$ , then x is

1. Lower limit
2. Assumed mean
3. Number of observations
4. Class size

Q. Find the mean deviation about the median for the following data: 3, 9, 5, 3, 12, 10, 18, 4, 7, 19, 21

1. 6.53
2. 5.27
3. 10.56
4. 12.96