Question

The table shows some households sorted according to their usage of electricity:

Electricity usage (units)	Number of households
80 – 90	3
90 – 100	6
100 – 110	7
110 – 120	10
120 – 130	9
130 – 140	4

Calculate the median usage of electricity.

Answer 1

Electricity usage (units)	Number of households
less than 80 – 90	3
less than 90 – 100	9
less than 100 – 110	16
less than 110 – 120	26
less than 120 – 130	35
less than 130 – 140	39

Half of the number of houses = 20

We have to find the electricity usage of the 20th house. According to this, we can divide