Hi all, i dont understand what is going on in this question. I understand the model is \eta=\alpha_i+\beta_iX_1 so i would have just calculated 0.298-0.076*19 but they have included the value for the intercept parameter and X1*19 this doesnt make sense to me at all, and this isnt like what is in the CMP, can anyone explain this? Thanks
Hi Molly An alternative way of writing eta=alpha_i+beta_i*X1 is eta=alpha_1'+beta_1'*X1+alpha_2'*Z1+alpha_3'*Z2+beta_2'*Z1*X1+beta_3'*Z2*X1 where Z1 is 1 if X2 is medium and Z2 is 1 if X2 is high, 0 otherwise So alpha_3=alpha_1'+alpha_3'=intercept+X2_High beta_3=beta_1'+beta_3'=X1+X1:X2 High alpha_1' and beta_1' are the base parameters and alpha_3' and beta_3' are added Hope this helps, thanks Andrea
