Merits,demerits and uses of range
Merits of Range:
(1) Range is rigidly defined.
(2) It is simple to understand and easy to calculate. It can be found by mere inspection.
(3) It can be calculated from extreme values only. So we need not know the details of the series to calculate the range.
(1) It is not representative since it is not based on all the observations of the series.
(2) It is not capable of further algebraic treatment.
(3) In case of open-end classes range cannot be determined exactly.
(4) It is not a stable measure of dispersion and is very much affected by the fluctuations of sampling. This is because it does not take into account all the sample items but only the extreme items of the sample.
Uses of Range:
- In quality control of manufactured products, range is used to study the variation in the quality of the units manufactured.
- Variations in money rates, share values, gold prices and exchange rates are commonly studied through range because the fluctuations in them are not very large.
- Range gives an idea of the variation between maximum and minimum levels of temperature. From day to day the range would not vary much and it is helpful in studying the vagaries of nature if variations suddenly rise or fall.