A CRD has three factors: A, B, and C. If all factors are fixed effects, we obtain the appropriate F ratio for testing for AB interaction by calculating

F = MS(AB)/MSE. What are the appropriate F-ratios for testing for (i) AC interaction and (ii) B main effects if:

(a) all factors are random effects factors;

(b) A and B are random effects factors, and C is a fixed effects factor;

(c) B is a random effects factor, and A and C are fixed effects factors.