Question

Draw Histogram from the following data:

Marks obtained	:	10-20	20-30	30-40	40-50	50-70	70-100
No. of Students	:	6	10	15	10	6	3

Answer 1

The data is given in the form of unequal class interval. So, we will first make appropriate adjustment in the frequencies to make the class intervals equal. The general formula for the adjustment of the frequency is as follows.
$\mathrm{Adjusted}\mathrm{Frequency}=\frac{\mathrm{Required}\mathrm{class}\mathrm{interval}\times \mathrm{Frequency}}{\mathrm{Actual}\mathrm{class}\mathrm{interval}}$

Marks	No. of Students	Adjusted Frequency
10−20	6	−
20−30	10	−
30−40	15	−
40−50	10	−
50−70	6	$\frac{10\times 6}{20}=3$
70−100	3	$\frac{10\times 3}{30}=1$