Dear Sir/Madam I want to test for linearity between continuous independent variables and the dependent variable in a logistic model (which contains a group of variables of different scales) using what is known as Box-Tidwell. What I understand is to have the product of each independent variable and its log and to add this product to the model to check its significance. However, I am not sure of the following points: If I have more than one continuous variable, shall I do that with them all and inter the products (terms) in one time, so that I will have a model with these continuous variables and their products with their logs. Or shall I do that separately for each variable? I think the significance will be different? And in case you have four or five independent variable of interval scale, you have different possible models. Then shall you test this linearity with all this models? Help me please

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