An experimenter wishes to run a three-component mixture experiment. The constraints in the component proportions are as follows:
(a) Set up an experiment to fit a quadratic mixture model. Use n = 14 runs, with four replicates. Use the D-criterion.
(b) Draw the experimental region.
(c) Set up an experiment to fit a quadratic mixture model with n = 12 runs, assuming that three of these runs are replicates. Use the D-criterion.
(d) Comment on the two designs you have found.