Electricity used by some families is shown in the following table. Find the mode for use of electricity.

Answer

The mode for the use of electricity is 72 units.

Explanation

Here, the maximum frequency (100) is in the class `60-80`.
` :. ` the modal class is `60-80`.
In the given example,
L = Lower class limit of the modal class = 60 ,
h = Class interval of the modal class = 20
`f_(1)` = Frequency of the modal class = 100
`f_(0)` = Frequency of the class preceding the modal class = 70
` f_(2)` = Frequency of the class succeeding the modal class = 80
Mode ` = L + [(f_(1) - f_(0))/(2f_(1) - f_(0) - f_(2))] xx h`
` = 60 + [(100 - 70)/(2(100) - 70 - 80)] xx 20`
` = 60 + (30/(200 - 150)) xx 20`
` = 60 + 30/50 xx 20 = 60 + 12 = 72`.