Draw a pie-diagram representing the relative frequencies (expressed as percentage) of the eight classes as given below :
12.6, 18.2, 17.5, 20.3, 2.8, 4.2, 9.8, 14.7
Here, total amount = 100.1%
The central angle = 
× 360°
Hence, the central angle for each activity will be calculated as follows
Class | Amount (in %) | Sector angle (degree) |
1 | 12.6 | 12.6/100.1 × 360 = 45.3 |
2 | 18.2 | 18.2/100.1 × 360 = 65.5 |
3 | 17.5 | 17.5/100.1 × 360 = 62.9 |
4 | 20.3 | 20.3/100.1 × 360 = 73 |
5 | 2.8 | 2.8/100.1 × 360 = 10.1 |
6 | 4.2 | 4.2/100.1 × 360 = 15.1 |
7 | 9.8 | 9.8/100.1 × 360 = 35.2 |
8 | 14.7 | 14.7/100.1 × 360 = 52.9 |
Steps for construction of representation of data in pie chart
Step 1: Draw the circle of appropriate radius.
Step 2 : Choose a radius anywhere inside the circle.
Step 3 : Now draw a sector of calculated component’s central angle. It is always preferable to choose component with largest central angle first and then continue in descending order of magnitude of their central angle.
Step 4: After drawing sectors, shade them with different colours and label them as shown in the figure.
