* simple random sampling;

proc surveymeans data = momsag n = 773 mean sum std;
  weight weight1;
  var momsag;
run;

* stratified random sampling;

data second138;
  input id _TOTAL_ oblevel;
  cards;
  1 42 1
  2 42 1
  3 42 1
  4 42 1
  5 99 2
  6 99 2
  7 99 2
  8 99 2
  9 99 2
  10 17 3
  11 17 3
  12 17 3
  13 17 3
  14 17 3
  15 17 3
  ;
run;

proc surveymeans data = hospsamp n = second138 sum ;
  weight weighta;
  strata oblevel;
  var births;
run;

proc surveymeans data = hospsamp n = second138 sum;
  weight weighta;
  strata oblevel;
  by oblevel;
  var births;
run;

* one-stage cluster sampling;

proc surveymeans data = tab9_1c n = 5 sum mean;
  weight wt1;
  cluster devlpmnt;
  var nge65 nvstnrs hhneedvn;
run;