7.2  8.8
  7.1  7.5
  9.1  7.7
  7.2  7.6
  7.3  7.4
  7.2  6.7
  7.5  7.2
Data from Box 9.5 Sokal and Rohlf 1995.
Age (days) at first reproduction in two
  genetic groups of Daphnia longispina.
MTB > read 'srbx9_5.dat' c1 c2;
SUBC> nobs=7.
MTB > stack c1 c2 c3
MTB > set  c4
DATA> (0 1)7
DATA> end
MTB > name c3 'age'  c4 'group'