Before going to deal with the various methods of correlation, it is necessary to know the various uses of correlation is statistical analysis which can be cited as follows:
- It is used in deriving precisely the degree, and direction of relationship between variables like price and demand, advertising expenditure and sales, rainfalls and crops yield etc.
- It is used in developing the concept of regression, and ratio of variation which help in estimating the values of one variable for a given value of another variable.
- It is used in reducing the range of uncertainty in the matter of prediction.
- It is used in presenting the average relationship between any two variables through a single value of co-efficient of correlation.
- In the field of economics it is used in understanding the economic behaviour, and locating the important variables on which the others depend.
- In the field of business it is used advantageously to estimate the cost of sales, volume of sales, sales price, and any other values on the basis of some other variables which are financially related to each other.
- In the field of science and philosophy, also, the methods of correlation are profusely used in making progressive developments in the respective lines.
- In the field of nature also, it is used in observing the multiplicity of the inter-related forces.