Question

A) If you want to consider regression models with just one independent variable, which variable would you consider to include into the model based on S criterion? (10 points)

B) If you want to consider regression models with just two independent variables, which variables would you include according to R-Sq(adj) criterion? (10 points)

a u i e I Mallows Vars R-Sq R-Sq(adj) Cp S e p y 1 81.3 79.8 1 58.0 54.5 1 9.5 2.0 2 85.783.0 282.9 79.8 2 69.2 63.6 3 88.4 84.9 6.1 7.8239 X 26.2 11.734 68.1 17.221 X 4.4 7.1630 X X 6.8 7.8193 XX 18.6 10.499 X X 4.0 6.7523 X X X

Answer 1

a)
the model with the lowest S-criterion is preferred,
here lowest S = 7.8239 for models with just one independent variable that is Price ,
hence
We will include Price

b)
the model with the highest R-sq(adj) is preferred,
R-sq is highest = 83 with variable Price and Promotional exp

hence we will include Price and Promotional exp