Snedecor and Cochran (1967) report weight gains for rats randomly assigned to one of four diets that varied in the amount and source of protein. The results were as follows:

Verify the results based on the R function pba2way mentioned in the example of Section 7.7.1.

Beef Beef Cereal Cereal Low High Low High 90 73 107 98 76 102 95 75 90 118 97 56 64 104 80 111 86 81 98 95 51 107 74 88 72 100 74 82 90 87 67 77 95 117 89 86 78 111 58 92