13.18. An article2 on predicting attitudes toward homosexuality used GSS data to model a response variable with a four-point scale in which homosexual relations were scaled from 1 = always wrong to 4 = never wrong, with xi = education

(in years), X2 = age,X3 = political conservative

(1 = yes,0 = no), X4 = religious fundamentalist

(1 = yes,0 = no), and X5 = whether live in same city as when age 16 (1 = ycs,0 = no). The prediction equation allowing interaction between x\ and X3 is y = 0.94 + 0.13x1 - O.Olxa + 1-10x3 - 0.38x4

— 0.15x5 — 0.12(x] X X3).

(a) Report the prediction equations for political conservatives and nonconservatives. Explain how these suggest that greater education corresponds to less negative views about homosexuality for nonconservatives but may have no effect for conservatives.

(b) The model without interaction had fit y = 1.53 + 0.09xi - 0-01x2 - 0.49x3

- 0.39x4 - 0.15x5.

Summarize the effect of each predictor.