The distribution below gives the weights of 30 students of a class.

$\frac{\mathbf{N}}{\mathbf{2}}=\frac{\mathbf{3 0}}{\mathbf{2}}=15$

Median class $=55-60$

Median $=\ell+\left\{\frac{\frac{\mathbf{N}}{\mathbf{2}}-\mathbf{c}}{\mathbf{f}}\right\} \times \mathbf{h}$

$=55+\left\{\frac{\mathbf{1 5}-\mathbf{1 3}}{\mathbf{6}}\right\} \times 5$

= 56.67