Cumulative Frequency Distribution
The total frequency of all classes less than the upper class boundary of a given class is called the cumulative frequency of that class. A table showing the cumulative frequencies is called a cumulative frequency distribution. There are two types of cumulative frequency distributions.
Less than cumulative frequency distribution:
It is obtained by adding successively the frequencies of all the previous classes including the class against which it is written. The cumulate is started from the lowest to the highest size.
More than cumulative frequency distribution:
It is obtained by finding the cumulate total of frequencies starting from the highest to the lowest class. The less than cumulative frequency distribution and more than cumulative frequency distribution for the frequency distribution are given below:
Less than C.F | More than C.F | |||||
Class Limit | $$f$$ | Class Boundaries |
Marks | C.F | Marks | C.F |
10 – 19 | 2 | 9.5 – 19.5 | Less than 19.5 | 2 | 9.5 or more | 48 + 2 = 50 |
20 – 29 | 4 | 19.5 – 29.5 | Less than 29.5 | 2 + 4 = 6 | 19.5 or more | 44 + 4 = 48 |
30 – 39 | 7 | 29.5 – 39.5 | Less than 39.5 | 6 + 7 = 13 | 29.5 or more | 37 + 7 = 44 |
40 – 49 | 10 | 39.5 – 49.5 | Less than 49.5 | 13 + 10 = 23 | 39.5 or more | 27 + 10 = 37 |
50 – 59 | 16 | 49.5 – 59.5 | Less than 59.5 | 23 + 16 = 39 | 49.5 or more | 11 + 16 = 27 |
60 – 69 | 8 | 59.5 – 69.5 | Less than 69.5 | 39 + 8 = 47 | 59.5 or more | 3 + 8 = 11 |
70 – 79 | 3 | 69.5 – 79.5 | Less than 79.5 | 47 + 3 = 50 | 69.5 or more | 3 |
50 |
leslie
September 30 @ 11:33 am
cf
48 + 2 = 50
where did he get that 48?
Razmi
October 5 @ 12:00 pm
48 is the cf> of Class limit 20-29
Vishal
October 11 @ 3:27 pm
He has added all the frequencies from the 20-29 Class Interval as we have to find the greater than cumulative frequency.
Hope This Helps
schadrak
February 3 @ 11:13 pm
How do get class boundaries of 19.5 – 39.5?
Mensah Aikins
July 19 @ 1:29 am
On the class boundaries the arrangement of numbers is wrong 19.5- 29.5, 29.5- 39.5 but it repeated itself there so kindly correct it
eMathZone
July 26 @ 8:50 pm
Fixed! Thank you for letting us know about this mistake.