Graphical Representation of Cumulative Frequency Distribution

Example: Consider the cumulative frequency distribution table as given below.


Marks
No of Students
0-10
5
10-20
3
20-30
4
30-40
3
40-50
3
50-60
4
60-70
7
70-80
9
80-90
7
90-100
8



Step 1: FInd the cumulative frequency.


Marks
No of Students (f)
Cumulative frequencies (cf)
0-10
5
5
10-20
3
8
20-30
4
12
30-40
3
15
40-50
3
18
50-60
4
22
60-70
7
29
70-80
9
38
80-90
7
45
90-100
8
53


Step 2: Mark the upper limit of the class interval on the horizontal axis ($x$ -axis) and corresponding
       cumulative frequencies on the vertical axis ($y$-axis). Join the points by a free hand to draw 
       a free curve. This curve is called cumulative frequency curve or an ogive.