Draw a frequency polygon to represent the following data :

Weight (in kg)	No. of workers
35 - 40	6
40 - 45	17
45 - 50	30
50 - 55	8
55 - 60	3

Frequency distribution table :

Steps to draw frequency polygon :

1. Take 2 cm along x-axis = 5 kg.

2. Take 2 cm along y-axis = 5 workers.

3. Find the mid-point of class intervals.

4. A kink is drawn near x-axis to show that the scale begins at 35.

5. Find points corresponding to given frequencies of classes and the mid-points of class-intervals, and plot them.

6. Join consecutive points by line segments.

7. Join first end point with mid-point of class 30 - 35 with zero frequency and join the other end with mid-point of class 60 - 65 with zero frequency.

The required frequency polygon is shown below :