In chapter 4.1 Simple Linear Regression we have to look at how to find a linear equation that explains the data. In this chapter, we will look at other forms of equations. The rationale is to try more regression lines and use the one with the higher value of R squared (obviously, if you find at least one with a good R squared).

Exponential

The exponential equation has a form expressed in the image1.

In this case the scatter plot with the regression line appear like the one in image2.

In this case, we have an R squared very high to say that the exponential regression explains the data.

Logarithmic

The logarithmic equation has a form expressed in the image3.

In this case, the scatter plot with the regression line appears like the one in the image4.

In this case, we have an R squared not so high, so for now the exponential regression line is better.

Power

The power equation has a form expressed in the image5.

In this case, the scatter plot with the regression line appears like the one in the image6.