Calculate the median from the following data:

Solution:

First we prepare the following cummulative table to compute the median.

Here, $N=250$

So, $\frac{N}{2}=125$

Thus, the cumulative frequency just greater than 125 is 127 and the corresponding class is $50-60$.

Therefore, $50-60$ is the median class.

Here, $l=50, f=31, F=96$ and $h=10$

We know that

Median $=l+\left\{\frac{\frac{N}{2}-F}{f}\right\} \times h$

$=50+\left\{\frac{125-96}{31}\right\} \times 10$

$=50+\frac{29 \times 10}{31}$

$=50+\frac{290}{31}$

$=50+9.35$

 

$=59.35$

Hence, the median is 59.35.