DATA Q; INPUT Trt $ @@; DO Replication = 1 TO 4; INPUT Y @; END; CARDS; Trt1 23 27 19 21 Trt2 18 17 20 15 Trt3 29 31 32 34

proc print; RUN;

If I run this in SAS, I obtain the following result:

Obs	Trt	Replication	Y
1	Trt1	5	21
2	Trt2	5	15
3	Trt3	5	34

Could you give me a break down of how this result is obtained?