Example 1: The marks obtained by 35 students in a class are given below. Construct the cumulative frequency table :
Marks obtained Number of students
0 1
1 2
2 4
3 4
4 3
5 5
6 4
7 6
8 3
9 2
10 1
Solution:
What is Cumulative Frequency in statistics 1
Example 2: The distribution of ages (in years) of 40 persons in a colony is given below.
Age (in years) Number of Persons
20-25 7
25-30 10
30-35 8
35-40 6
40-45 4
45-50 5
(a) Determine the class mark of each class
(b) What is the upper class limit of 4th class
(c) Determine the class size
Solution: (a) Class marks are
What is Cumulative Frequency in statistics 2
= 22.5, 27.5, 32.5, 37.5, 42.5, 47.5
(b) The fourth class interval is 35–40. Its upper limit is 40
(c) The class size is 25 – 20 = 5