Frequency Distribution: Definition And Why It Is Important In Statistics

What is frequency distribution?

Frequency distribution is the way in which a set of data is classified into different mutually exclusive groups. That is, if a piece of data belongs to one group, it cannot belong to another.

Know Some Important Points

• Frequency distribution organizes data into mutually exclusive groups.
• There are several types of frequencies: absolute, relative, absolute cumulative, and relative cumulative.
• Facilitates the interpretation of large volumes of data.

Frequency distribution: Simple explanation

In other words, frequency distribution is a way of organizing data into non-overlapping categories. This is done to better understand how that data is distributed across different groups. This can help you visualize the information you collect in a clear and orderly manner, making it easier to analyze and understand.

To see this in an example, a group of people can be grouped according to their age in ranges of 18 to 25 years, 26 to 40 years, 41 to 60 years, and 61 years and older.

It should be noted that the frequency distribution is usually carried out with respect to a statistical sample, although it could also be based on an entire population.

Types of frequency distributions

The types of frequency distributions are as follows:

• Absolute frequency (fi): This is the number of observations that belong to each group. It is also interpreted as the number of times an event is repeated. For example, continuing with the previous case, it may be that out of a group of 100 people, 20 of them are between 26 and 40 years old.
• Relative frequency (hi): It is calculated by dividing the absolute frequency by the number of data, for example, returning to the situation presented above, 20/100 is equal to 0.2 or 20%.
• Cumulative absolute frequency (Fi): It results from adding the absolute frequencies of a class or group of the sample (or population) with the previous one or ones. For example, to calculate the cumulative absolute frequency of the third group, the absolute frequencies of the first, second, and third groups are added.
• Accumulated relative frequency (Hi): This is the result of adding the relative frequencies, as explained for the accumulated absolute frequency. For example, to calculate the accumulated relative frequency of the fourth group, the relative frequencies of the first, second, third, and fourth groups are added.

Example of frequency distribution

Let’s look at an example of a frequency distribution table: