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Statistics

Calculating Cumulative Frequency from Grouped Frequency Distribution Table

When the data is very large, we take the help of the frequency distribution table to represent the same. Frequencies of different classes are given in this table, which helps us to extract the desired information.

Apart from this, there is more to learn about frequency. For the same, let us consider the data collected from a random survey conducted about the number of persons of different ages in a locality. The data is represented in the following table.

 Age (in years) 5 − 15 15 − 25 25 − 35 35 − 45 45 − 55 55 − 65 Number of persons 7 19 17 12 8 2

(Table 1)

Now, if we want to find out the number of people of age more than 35 or that of less than 65 then how would we proceed?

This can be done by simply adding and subtracting the frequencies of the required classes. We have a method of calculating the same by finding the cumulative frequency.

Cumulative frequency for a class is the total of frequencies above or below…

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