The dataset perch.dat contains data on the size of perch caught in a lake in Finland.  The variables are:

   observation number (integers 104-159)
   weight in grams
   length n centimeters
   width in centimeters

The columns in the datafile are separated by tabs rather than spaces, so you
will need to use the "delimiter" option on your infile statement in order
to read the file correctly:

data perch ;
infile 'c:\temp\perch.dat' delimiter = '09'x ;
input obs weight length width 3.1 ;
run ;