in such a way that we could not predict what treatment each person would receive, and every
patient was equally likely to receive drugs or surgery.
You can also choose some, but not all, of the integers in a certain range. The statements
below chooses 10 numbers at random from 1, 2, 3, ..., 20. In this case, SAS chose (2 6 16 13
3 7 11 10 12 17).