points on a curvy line.
There are two mathematical laws that can be used to depict data represented on a scatterplot:
- linear law: y = m·x + b
- exponential law: y = kaˣ
They have a few common characteristics:
- they depend on parameters (m and k);
- they describe a direct proportionality;
The difference is that for a linear law it is constant the ratio between the increment on the y-values and the increment on the x-values, resulting in a straight line; on the contrary, for an exponential law it is constant the ratio between the value of the function at (x + 1) and the value of the function at x, therefore the ratio between the increments keeps increasing, resulting in a curvy line.Hence, if the data follow an exponential model, on a scatterplot the points would lie on a curvy line.