The distribution below gives the weight of 30 students in a class.

Solution:

We prepare the cumulative frequency table, as given below.

We have, $N=30$

So, $\frac{N}{2}=15$

Now, the cumulative frequency just greater than 15 is 19 and the corresponding class is $55-60$.

Therefore, $55-60$ is the median class.

Here, $l=55, f=6, F=13$ and $h=5$

We know that

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

$=55+\left\{\frac{15-13}{6}\right\} \times 5$

$=55+\frac{2 \times 5}{6}$

$=55+\frac{10}{6}$

$=55+1.667$

 

$=56.667$

Hence, the median weight of students is 56.67 kg.