options ls=72 ps=50;
data;
input a b fat @@;
cards;
1  1  5.3
1  1  5.6
1  2  5.7
1  2  5.7
1  3  5.3
1  3  5.2
2  1  5.2
2  1  5.1
2  2  5.3
2  2  5.4
2  3  4.9
2  3  5.2
3  1  5.2
3  1  5.2
3  2  5.6
3  2  5.2
3  3  5.4
3  3  5.6
proc glm;
classes a b;
model fat=a|b;
random a a*b/q test;
run;