Another statistical idea which is very basic and important while finding a relation between two variables is called correlation. In a way, one can say that the concept of correlation is the premise of predictive modelling, in the sense that the correlation is the factor relying on which we say that we can predict outcomes.
A good correlation between two variables suggests that there is a sort of dependence between them. If one is changed, the change will be reflected in the other as well. One can say that a good correlation certifies a mathematical relation between two variables and due to this mathematical relationship, we might be able to predict outcomes. This mathematical relation can be anything. If x and y are two variables, which are correlated, then one can write:
If f is a linear function, then a and b are linearly correlated. If f is an exponential function, then a and b are exponentially correlated:
The degree of correlation between the two variables x and y is quantified...
