Glossary term
Frequency Distribution: Meaning and Definition
Reviewed and approved by Dr. Anamika ShrivastavaPublished Last updated
A frequency distribution is a table that shows the number of observations falling in each class or value of a variable. It condenses raw data into a readable form. Its parts include class limits, class interval, class mark and frequency, and it is the basis for graphs and averages.
In more detail
Grouping raw data into classes shows its shape at a glance: where values cluster, how spread out they are and whether it is symmetric. The price of grouping is loss of detail, since values within a class are treated alike. Cumulative frequencies, built from the table, support medians and ogives.
Example
Of 30 students, 1 studies 0–4 hours, 9 study 4–8, 11 study 8–12, 8 study 12–16 and 1 studies 16–20 hours a week. These five classes with their counts form a frequency distribution.
Key points
- Class mark = (upper + lower) ÷ 2.
- Class interval = upper limit − lower limit.
- The frequencies add up to the number of observations.
Common mistake
Choosing overlapping or unequal classes without adjusting. This distorts the picture.
Related terms
Where it is explained
This term is explained in Class 11 Statistics Chapter 3: Organisation of Data.