Business Statistics

Chapter 4 | Measures of Dispersion 125

However, quartiles are less affected by the presence of extreme values. Hence, quartile deviations

possess some merits as well as some demerits. The following is a list of the merits and demerits of

quartile deviation.

4.4.8.1  Merits

1. It is easy to calculate and simple to understand.

2. Quartile deviation is least affected by the presence of extreme values.

4.4.8.2  Demerits 

1. Quartile deviation is not based on all the observations. In fact it ignores 50% of items in any

distribution. In other words, we can say that it does not cover the rst 25% and the last 25% of the

items in a series.

2. ...