Hello all, I am trying to conduct a two-way ANOVA with 8 observations, independent variables Income (5 levels) and Age (4 levels), and dependent variable Rates. The independent variables started out as numbers, so to make them categorical I used statements such as if income<35000 and income>40000 then inlevel='First'; I then used the following procedure: proc glm data=works; class income age; model rates = income age income*age; run; The output was working fine until it hit the interaction effects. In the SS output, the interaction effects are just showing missing values. Does this mean I have too few observations and the interaction effects are too small? Or should I not be using categorical variables? This is all using SAS University, by the way. Thanks for your help!
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