Determine a model of how sales volume (svol) depends on the number of contacts a salesperson has. Try a model of the form Y = a + b X and one of the form Y = a + b X + cX2.

For Y = a + b X R2 =

Model =

Standard Errors of Coefficients =

For Y = a + b X + cX2 R2 =

Model =

Standard errors of coefficients =

Which is the best model?

What do you conclude about the plausibility of this model over the long run?