libname sasdata2 "e:\sasdata2";

data sasdata2.tecumseh_long;
  set sasdata2.tecumseh;

  keep id sex age marital height weight round;

  if age1 not=. then do;
  age     = age1;
  marital = marital1;
  height  = htcm1;
  weight  = wtkg1;
  round = 1;
  output;
  end;

  if age2 not=. then do;
  age     = age2;
  marital = marital2;
  height  = htcm2;
  weight  = wtkg2;
  round = 2;
  output;
  end;

  if age3 not=. then do;
  age     = age3;
  marital = marital3;
  height  = htcm3;
  weight  = wtkg3;
  round = 3;
  output;
  end;

run;

proc print data=sasdata2.tecumseh_long(obs=25);
run;

proc means data=sasdata2.tecumseh_long;
  class round;
run;