Merits
- It is easy to plot even by a beginner.
- It is very easy and simple to understand even by a single glance.
- Abnormal values in a sample can be easily detected.
- We can find the value of some dependent variables if unknown.
- Values of extreme terms do not effect when correlation is calculated by this method
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Demerits
- This method depicts only if relation is positive or negative or no relation. But degree of correlation can’t be predicted.
- No mathematical or Algebraic Treatment is possible to the result.
- The method is useful only when number of terms is small i.e. it can’t be applied to 3-4 terms.
- The method is also useless when number of terms is very big i.e. in hundreds.