Power Regression

The power regression option finds the equation of the form y = axb 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 and y must be greater than zero. (This is because the method for determining the values of a and b in the regression equation is a least-squares fit on the values for ln x and ln y.)

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 Power 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 power equation for this data is approximately y = 7.01x0.8.