Reconsider the crystal growth experiment from Exercise 8.18. Suppose that x3 z is now a noise variable, and that the modified experimental design shown in Table 8E.9 has been conducted. The experimenters want the growth rate to be as large as possible, but they also want the variability transmitted from z to be small. Under what set of conditions is growth greater than 90 with minimum variability achieved?

Teater he has variatility Continued X1 X2 N 1 1 1 75 Table 8E.9 Crystal Growth Experiment for Exercise 8.19 -1.682 0 0 65 1.682 0 0 82 X1 X2 Z 0 -1.682 o 68 -1 -1 66 0 1.682 0 63 -1 -1 1 70 0 0 0 83 1 -1 78 0 0 0 90 -1 1 1 60 0 0 0 87 1 1 -1 80 0 0 0 88 1 -1 1 70 0 0 0 91 1 1 -1 100 0 0 0 85 Teater he has variatility Continued X1 X2 N 1 1 1 75 Table 8E.9 Crystal Growth Experiment for Exercise 8.19 -1.682 0 0 65 1.682 0 0 82 X1 X2 Z 0 -1.682 o 68 -1 -1 66 0 1.682 0 63 -1 -1 1 70 0 0 0 83 1 -1 78 0 0 0 90 -1 1 1 60 0 0 0 87 1 1 -1 80 0 0 0 88 1 -1 1 70 0 0 0 91 1 1 -1 100 0 0 0 85