The range is defined as the difference between the maximum and minimum values in a set of numbers.
Range = Highest value – Lowest value.
Find the range in the following set of data: 12, 6, 19, 8, 24, 16, 36, 9, 40, 6, 50, 48, 12.
Highest/Maximum value = 50
Lowest/Minimum value = 6
⸫ Range = 50 – 6
Characteristics of Range
- The range is easy to understand and simple to calculate because its value is determined by the two extreme items.
- Its value may greatly change if an extreme value (either highest or lowest) is withdrawn or a fresh value is added. It is a highly unstable measure of dispersion.
- It gives no indication of how the values within the two extremes are distributed.
Merits of Range
- It is very easy to calculate and simple to understand.
- It is rigidly defined.
- It is the least time-consuming measure of dispersion.
Demerits of Range
- It is not based on all the items in the distribution. Therefore, it is not reliable.
- It is too affected by the extreme values.
- It is too affected by sampling fluctuations.
- It cannot be computed in the case of open-end distribution.
- It does not reveal anything about the variability of other data.