If the F-ratio for factor A has df = 1,40 and the F-ratio for factor B has df = 3,40,then the F-ratio for the interaction must have df = 2,40.

Question

If the F-ratio for factor A has df = 1,40 and the F-ratio for factor B has df = 3,40,then the F-ratio for the interaction must have df = 2,40.​

Quizplus · Accepted Answer

The F-ratio for the interaction does not necessarily have to have df = 2,40. The degrees of freedom for the interaction depend on the design of the study and cannot be determined simply by knowing the degrees of freedom for the main effects (factor A and B).

If the F-Ratio for Factor a Has Df = 1,40