The frequency distribution is as follows:
| Class interval |
Frequency |
| 20-25 |
30 |
| 25-30 |
24 |
| 30-35 |
52 |
| 35-40 |
28 |
| 40-45 |
46 |
| 45-50 |
10 |
Consider the class intervals on the X – axis and frequency on the Y- axis and draw rectangles which provides the required histogram.
To construct a frequency polygon, take 15 – 20 and 50 – 55 as imaginary class intervals with frequency zero and join the midpoints of rectangles.
So the frequency polygon is as given below:
