The following table gives the monthly consumption of electricity of 100 families

The following table gives the monthly consumption of electricity of 100 families:

Find the median of the above data. 

Answer

$$ \frac{N}{2} = \frac{100}{2} = 50 $$

Median class is 160-170

L = 160, h = 10, cf = 31, f = 28

$$ \text{Median } = L + \frac{\frac{N}{2} - cf}{f} \times h $$

$$ = 160 + \frac{50 -31}{28} \times 10 = 160 + \frac{19}{28} \times10 $$

= 166.8