(Data file: Wool) Refer to the Wool Data discussed in Section 5.2. Write out in full the main effects and the second-order mean functions, assuming that the three predictors will be turned into...

(Data file: Wool) Refer to the Wool Data discussed in Section 5.2.

Write out in full the main effects and the second-order mean functions, assuming that the three predictors will be turned into factors, each with three levels. This will require you to define appropriate dummy variables and parameters.

For the two mean functions in write out the expected change in the response when len and amp are fixed at their middle levels, but load is increased from its middle level to its high level.