Box, Hunter, and Hunter (see References) studied the effects of catalyst charge (10

Chapter 9, Problem 9.5-5

(choose chapter or problem)

Box, Hunter, and Hunter (see References) studied the effects of catalyst charge (10 pounds = 1, 20 pounds = +1), temperature (220 C = 1, 240 C = +1), pressure (50 psi = 1, 80 psi = +1), and concentration (10% = 1, 12% = +1) on percent conversion (X) of a certain chemical. The results of a 24 design, in standard order, are x1 = 71, x2 = 61, x3 = 90, x4 = 82, x5 = 68, x6 = 61, x7 = 87, x8 = 80, x9 = 61, x10 = 50, x11 = 89, x12 = 83, x13 = 59, x14 = 51, x15 = 85, x16 = 78. (a) Estimate the main effects and the two-, three-, and four-factor interactions. (b) Construct an appropriate qq plot and assess the significance of the various effects.