Measures of Dispersion for Ungrouped Data
Range
The difference between the largest and smallest values in a data set.
| English | Range |
|---|---|
| Bahasa Melayu | Julat |
| 中文 | 全距 |
How it is used
For the test marks 5, 8, 12, 15 and 20, the range is 20 − 5 = 15 marks, showing how far the highest score sits above the lowest.
Where it shows up in SPM
In Measures of Dispersion for ungrouped data. In Paper 1 it is a quick one-mark calculation from a small list; in Paper 2 it often opens a question before you compare the spread of two data sets.
Don't confuse it with
Open the chapter: Measures of Dispersion for Ungrouped Data →
Frequently asked questions
Is the range affected by extreme values?
Yes, very much. Because it uses only the largest and smallest values, one unusually high or low reading changes the range completely.
That is why the interquartile range or standard deviation is often preferred when a data set contains outliers.
Do I write the range with units?
Yes. The range keeps the same unit as the data.
If the marks are out of 100, the range is written in marks; if the data is heights in cm, write the range in cm. A bare number without units can lose a mark in Paper 2.