The marks obtained (out of $100$) by a class of $80$ students are given below:

Marks	Number of students
$10-20$	$6$
$20-30$	$17$
$30-50$	$15$
$50-70$	$16$
$70-100$	$26$

Construct a histogram to represent the data above.

(N/A) Here,the class intervals are of unequal width. So,we shall compute the adjusted frequencies of each class. The minimum class size is $20-10=10$. The adjusted frequencies are computed by using the following formula:
$\text{Adjusted frequency} = \frac{\text{Minimum class size}}{\text{Class size}} \times \text{Frequency of the class}$
The adjusted frequencies are computed in the following table:

Marks	Number of students (Frequency)	Adjusted Frequency
$10-20$	$6$	$\frac{10}{10} \times 6 = 6$
$20-30$	$17$	$\frac{10}{10} \times 17 = 17$
$30-50$	$15$	$\frac{10}{20} \times 15 = 7.5$
$50-70$	$16$	$\frac{10}{20} \times 16 = 8$
$70-100$	$26$	$\frac{10}{30} \times 26 \approx 8.67$

Now,we construct rectangles with class limits as bases and respective adjusted frequencies as heights.