Cumulative Frequency Series
A series whose frequencies are continuously added corresponding to the class intervals is known as Cumulative Frequency Series.
Conversion of a Simple Frequency Series into Cumulative Frequency Series
A simple frequency series can be converted into a cumulative frequency series. There are two ways through which it can be done. These are as follows:
- Expressing the cumulative frequencies on the basis of the upper limits of the class intervals. For example, expressing 10-20, 20-30, and 30-40 as Less than 20, Less than 30, and Less than 40.
- Expressing the cumulative frequencies on the basis of lower limits of the class intervals. For example, expressing 10-20, 20-30, and 30-40 as More than 20, More than 30, and More than 40.
Example of Frequency Distribution in Cumulative Frequency Series
Convert the following simple frequency series into a cumulative frequency series using both ways.
Solution:
Method-I (On the Basis of Upper Limits)
Method – II (On the Basis of Lower Limits)
Conversion of Cumulative Frequency into Simple Frequency Series
To attain the frequency against a specific class interval of a cumulative frequency series, it can be converted into a simple frequency series.
Example:
Determine the frequency of the following cumulative frequency series.
Solution:
Types of Frequency Distribution
It is not always possible for an investigator to easily measure the items of a series or set of data. To make the data simple and easy to read and analyze, the items of the series are placed within a range of values or limits. In other words, the given raw set of data is categorized into different classes with a range, known as Class Intervals. Every item of the given series is put against a class interval with the help of tally bars. The number of items occurring in the specific range or class interval is shown under Frequency against that particular class range to which the item belongs.
Table of Content
- Example of Frequency Distribution
- Types of Frequency Distribution
- 1. Exclusive Series
- 2. Inclusive Series
- 3. Open End Series
- 4. Cumulative Frequency Series
- 5. Mid-Value Frequency Series
- 6. Equal and Unequal Class Interval Series
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