Consider again the data in Problem 4.
a. How would you compute appropriate cross-product variables to allow testing of whether an interaction exists between age and faculty rank?
b. State the associated regression model.
c. Using a computer, fit the model. Provide estimates of the regression coefficients.
d. Provide a multiple partial F test for interaction, controlling for age and faculty rank. Use α = .05.
e. Does the F test in part (d) indicate that ANACOVA is valid?
In Problem 4

Group 1: Full Professors (ZI 1,22 = 0) 52 49 45 41 41 40 39 Age ) 65 61 47 Tolerance (Y) 3.03 2.70 4.3 2.70 5.09 402 3.71 5.52 5.294.62 1) Group 2: Associate Professors (ZI = 0,22 30 35 49 31 42 39 49 Age C0) 34 31 Tolerance () 4.62 5.22 4.85 4.51 5.12 4.47 4.50 4.88 5.17 5.21 Group 3: Assistant Professors (Z1 = Z2 = 0) 25 30 31 27 Age ) 26 48 32 Tolerance (V) 5.20 5.86 4.61 455 4.47 5.71 4.77 5.82 3.67 5.29