Measures of Dispersion for Grouped Data
Modal class
The class interval with the highest frequency in grouped data.
| English | Modal class |
|---|---|
| Bahasa Melayu | Kelas mod |
| 中文 | 众数组 |
How it is used
For classes 1–10, 11–20, 21–30, 31–40, 41–50 with frequencies 3, 7, 12, 6, 2, the class 21–30 has the highest frequency, 12, so it is the modal class.
Where it shows up in SPM
In grouped-data statistics, Form 5. It is a short Paper 1 or Paper 2 answer: identify the interval with the greatest frequency.
On a histogram it is simply the tallest bar (with equal widths), and the mode itself can be estimated by drawing crossing lines from the tops of the neighbouring bars.
Don't confuse it with
Open the chapter: Measures of Dispersion for Grouped Data →
Frequently asked questions
Can there be more than one modal class?
Yes. If two class intervals share the same highest frequency, the data has two modal classes.
If the top frequency belongs to a single interval, there is just one modal class, as in the example where 21–30 alone has frequency 12.
Is the modal class the same as the mode?
No. The modal class names an interval, such as 21–30, while the mode is a single number inside it.
For grouped data you can only estimate the mode, usually by construction on a histogram, because the exact values are unknown.