In the transformed scale, fit both the first-order model and the second-order model, and compute an F-test comparing these two models. This is a nonstandard test because it is simultaneously testing...

In the transformed scale, fit both the first-order model and the second-order model, and compute an F-test comparing these two models. This is a nonstandard test because it is simultaneously testing all interactions to be equal to zero. Then provide an effects plot for the len by amp interaction. This will of course be three parallel lines. Then redraw this effects plot with cycles rather than log(cycles) on the horizontal axis, and compare with the effects plot you drew in.

(Data file: fuel2001) Justify transforming Miles in the fuel data.