Data Handling

Pie Charts

 

A pie-chart gives a clear visual impression of the size of a set of data inside a circle. Since each section of data is clearly marked in a distinct colour, it is a powerful way of showing the size of data.


E.g. Suppose that the marks obtained by a student in a school test is as follows:



Subject Marks
Maths 70
Physics 60
Economics 40
IT 50
Geography 20


Now, in order to show the data in a pie chart, we can use the following simple procedure:


The total of marks is 240.
240 marks --> 3600
1 mark --> 360 /240 = 1.5 0

Based on this, the size of pie for each subject is, in proportion to each mark, is as follows:

 

Subject Size of the Pie in degrees
Maths 105
Physics 90
Economics 60
IT 75
Geography 30

Now, we can draw a pie chart to represent the data easily. It is shown below:





If you want to practise your own, please put data into the the boxes and then click the button.


Item Data
Item 1
Item 2
Item 3
Item 4
Item 5