To fit a regression line
main topic     example 

1    In the graph dialog box, click Data View.

2    Click the Regression tab.

3    Under Model Order, choose Linear, Quadratic, or Cubic, based on the model you want to fit.

4    Check or uncheck Fit intercept, to include or exclude the intercept (constant) in the model. If you uncheck Fit intercept, the regression line passes through the origin (x = 0, y = 0)

5    Click OK in each dialog box.