Select the ratios whose simplest form is 8/7

a. By R, we have µ.1 = µ.2 = µ.3 = µ.4 = µ.. = 269. Since β j = µ. j − µ.., we have β1 = β2 = β3 = β4 = 0. The results imply that factor B has no main effects.

b. The treatment means plot is shown below:

The lack of parallelism between the two curves reflects interaction effects. The interactions are important since the height difference between the two curves changes drastically.

c. The transformed treatment means plot is shown below:

This transformation is not helpful in reducing the interactions.