 |
Data, Tables and Graphs - 2. Graphical Representation of Data
Page 44 of 44 |
|
|
|
|
2.3.5 - Pie Chart |
|
|
As the name suggests this graphic comprises a circle divided into a number of sectors, as many sectors as there are classes in the frequency table of the sample under analysis. The sector angles are proportional to the class frequency. For example, a class with a relative frequency equal to 0.20 will have a pie chart sector with an angle of 360x0.20 = 72 degrees. It is a representation that is essentially used for qualitative data. |
|
|
|
|
|
| Example: Occupation of the employees of a secondary school. |
| Classes |
Absolute frequency |
Relative frequency |
| AE (Teacher's Assistant) |
20 |
0.47 |
| Ad (Administrative Officer) |
12 |
0.29 |
| AS (Social Worker) |
7 |
0.17 |
| Op (General manual worker) |
3 |
0.07 |
| Total |
42 |
1.00 |
|
 |
This representation indicates the relative frequency of the respective class in addition to the occupation. |
|
|
|
|
|
|
