In order to test for the significance of a regression model involving 8 independent variables and 121 observations, the numerator and denominator degrees of freedom (respectively) for the critical value of F are
A)8 and 121
B)7 and 120
C)8 and 112
D)7 and 112

Question

Quizplus · Accepted Answer

The numerator degrees of freedom equal the number of independent variables, which is 8. The denominator degrees of freedom equal the total sample size minus the number of independent variables, which is 121-8=113. However, since we are estimating the intercept term as well, we subtract an additional 1 from the denominator degrees of freedom, resulting in 113-1=112. Therefore, the answer is C, 8 and 112.

In Order to Test for the Significance of a Regression