Draw histograms for the following frequency distributions :

Class mark	Frequency
16	8
24	12
32	15
40	18
48	25
56	19
64	10

Since, the difference between the values of any two consecutive class marks is 8 (24 - 16).

Therefore, subtract $\dfrac{8}{2}$ = 4, from each class mark to get the lower limit of the corresponding class interval and add 4 to each class mark to get the upper limit.

Frequency distribution table :

Steps of construction of histogram :

1. Since, the scale on x-axis starts at 12, a break (kink) is shown near the origin on x-axis to indicate that the graph is drawn to scale beginning at 12.

2. Take 1 cm along x-axis = 8 units.

3. Take 1 cm along y-axis = 5 units.

4. Construct rectangles corresponding to the above continuous frequency distribution table.

The required histogram is shown in the below figure: