Range is defined as the difference between the value of the smallest item and the value of the largest item included in the distribution. It is the simplest method of measuring dispersion. Symbolically,
• Range= Largest value (L) – Smallest Value (S)
The relative measure corresponding to range, called the coefficient of range, is obtained by applying the following formula:
• Coefficient of Range= (L- S)/ (L S)
Merits of Range:
1. It is simple to understand and easy to calculate.
2. It is less time consuming.
Demerits of Range:
1. It is not based on each and every item of the distribution.
2. It is very much affected by the extreme values.
3. The value of Range is affected more by sampling fluctuations
4. Range cannot be computed in case of open-end distribution.