C. The Example
I have a sample of n=60 and p=2 independent variables.
I have d.f.=2 in the numerator and d.f.=57 in the denominator.
So at the .05 level of significance, my critical F is approximately 3.15.
If my test F is greater than 3.15, I reject the null and conclude that at least one of my coefficients is NOT zero and my model has overall significance.