a. Suppose that a two-way ANOVA is to be performed, with five-year postoperative change in refractive error as the dependent variable (Y) and diameter of clear zone (CLRZONE) and baseline average corneal curvature (BASECURV = 1 if curvature is < 43 diopters; = 2 if curvature is between 43 and 44 diopters; and = 3 if curvature is > 44 diopters) as the two factors. State precisely the ANOVA model. Are the factors fixed or random?
b. In the SAS output that follows, complete the ANOVA table.
c. Analyze the data to determine whether there are significant main effects due to clear zone and baseline curvature and whether these factors significantly interact. Use α = .10.