If you wish to develop a regression model in which the High School Class standing is a qualitative variable with 4 possible levels of response, then you will need to include how many dummy variables?
A) 6
B) 5
C) 4
D) 3
E) none of these

Question

Quizplus · Accepted Answer

When a qualitative variable has k possible levels of response, we need to include (k-1) dummy variables in the regression model. In this case, High School Class standing has 4 possible levels, so we need to include (4-1) = 3 dummy variables in the model. Therefore, the answer is D.

If You Wish to Develop a Regression Model in Which