14. Fit the general quadratic model to the ceramic pipe data in Table 10.12.

(a) Fit the model with proc mixed including the random whole plot eects.

(b) Fit the model in proc rsreg ignoring the random whole plot eects.

(c) Verify that the regression coecients are the same for both models, but that the standard errors of the coecients are dierent.

(d) What procedure would you use to t the model in order to determine if the model can be simplied by dropping a factor?

(e) What procedure would you use to do a canonical or ridge analysis to determine the strongest pipe?