 Download: SegRegA Go to: Software & models General articles & manuals Artiículos (in Spanish, en Español) Published reports & cases Particular reports & cases FAQ's & answers Home page 



The equation in the potato example (above) is
found by a transformation raising X to the power 0.5
so that W = X ^ 0.5 and then performing a
cubic regression of Y on W with the result: Y = 0.537 W ^ 3  4.70 W ^ 2 + 11.2 W + 1.84 and hence: Y = 0.537 X ^ 1.5  4.70 X + 11.2 X ^ 0.5 + 1.84 which is now no longer a third degree (cubic) equation. See also this potato article 