Answer:
b. 15
Step-by-step explanation:
Given that:
There are 4 independent variables, then the subset regression total is 2⁴ = 16 attainable regression model.
However, out of these 16 regression models, 1 Model contains no predictors which only intercept 3 Model with [tex](X_1), (X_2), (X_3)[/tex], 3 Model with[tex](X_1,X_2), (X_1,X_3), (X_2,X_3)[/tex]. and 1 Model which comprises all the independent variables.
Therefore, when applying best subsets regression with a model that possesses four (4) independent variables, the number of different combinations of regression models that can be considered is 15.
