Logarithmic Regression

The logarithmic regression option finds the equation of the form y = a + b ln x that best fits a set of data. Press to choose the statistics application. Choose fit data... and press . Enter the data.

The values of x must, of course, be greater than zero.

The data shown here are the points {(2,11.4), (3,17), (5,27.3), (7,36.1), (11,47.7), (13,49.9)}.

Press to choose a statistics calculation option.

Select Logarithmic Fit and press .

Press to calculate the regression.

The regression equation is in level 3 of the stack, the correlation in level 2, and covariance in level 1. To view the entire correlation press . Press again to see the regression equation itself.

Therefore, the best-fit logarithmic equation for this data is approximately y = -5.45 + 21.54 ln x.