[R] Regression w/ interactions

[Michael Dykes]

I have a project due in my Linear Regression class re: regression on a data
set & my professor gave us a hint that there were *exactly *2 sig
interactions. The data set is attached. We have to find which predictors are
significant, & which 2 interactions are sig. Also, I nedd some guidance for
this & selecting the best model. I tried the `full' model, that being:
z=lm(y~x1+x2+x3+x4+x1*x2+x2*x3...+x3*x4). I then ran an anova(z), &
summary(z). My R^2 & R^2_a were *really* low. I am not sure how to do PRESS,
AIC & Cp in R yet though. Any help would be appreciated.
-- 
In Christ,
Michael D
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