Quartile DeviationQuartile deviation is another measure of dispersion. It is given by
Relative measure of dispersion based on quartiles is the coefficient of quartile deviation (Q.D.).
The quartiles of a variable are 45, 52 and 65, respectively. Find its quartile deviation and coefficient of quartile deviation.
Given: Q1 = 45, Q2 = 52, Q3 = 65
- It is easy to calculate.
- It can be easily understood.
- It is not affected by the extreme values.
- It has a special utility in measuring variation in case of frequency distribution with open-end classes at both ends.
- It is not based on all the observations.
- It is not the representative value of data.
- It is not capable of algebraic treatments.
- It is affected by sampling fluctuations.