Belloto et al. (1985) studied the relation between y= Soluability of pheno-

barbital and mixture components x1: ethanol, x2: propylene gycol and x3:

water.

(a) Use the mixexp package to list the experiments required to t a linear Schee model.

(b) Use the mixexp package to list the experiments required to t a Schee quadratic model.

(c) Use the mixexp package to list the experiments required to t a special cubic model.

(d) Use the mixexp package to list the experiments required to t a full cubic model.