#!usr/bin/perl -w
use strict;

while(<DATA>)
{
    next if /^\s$/;        # skip blank lines
    
    my ($SAMPLE_NAME, $SIZE) = (split /\s+/)[1,3]; 
    
    # print line if $SIZE isn't numeric, e.g. "SIZE"
    # or if it is a number, then must meet min, max criteria
    
    if ($SIZE =~ /^[^0-9-.]/ or ( $SIZE > 2 and $SIZE <5)) 
    {
       print "$SAMPLE_NAME $SIZE\n";
    }
}

=prints
SAMPLE_NAME SIZE
U7345 4.333
=cut 
        
__DATA__
ID SAMPLE_NAME EFFECTS SIZE
001 U7654 NEGATIVE 5.666
002 U7345 POSITIVE 4.333
003 U7674 NEGATIVE 1.696
002 U7845 POSITIVE -4.333