From the given data, we can observe that the class intervals have varying widths. The areas of the rectangles should be proportional to the frequencies in a histogram.
For example, when the class size is 5, the length of the rectangle is 10. So when the class size is 1, the length of the rectangle will be 10/5 × 1 = 2
| Age (in years) | Number of children | Width of class | Length of rectangle |
|---|---|---|---|
| 1 - 2 | 5 | 1 | (5 x 1)/1 = 5 |
| 2 - 3 | 3 | 1 | (3 x 1)/1 = 3 |
| 3 - 5 | 6 | 2 | (6 x 1)/2 = 3 |
| 5 - 7 | 12 | 2 | (12 x 1)/2 = 6 |
| 7 - 10 | 9 | 3 | (9 x 1)/3 = 3 |
| 10 - 15 | 10 | 5 | (10 x 1)/5 = 2 |
| 15 - 17 | 4 | 2 | (4 x 1)/2 = 2 |
Steps of construction :
Take the age of children on x-axis, using scale 1 unit = 1 year.
Take proportion of children per 1 year interval on y-axis, using scale 1 unit = 1 child.
To represent our first Head, i.e., (1 - 2) we draw a rectangular bar with width 1 unit and length 5 units.
Similarly, other Heads are represented without leaving a gap between two consecutive bars, according to the table.
