my @data; my $avg; while () { chomp; my $tmp = [split /:/]; $avg += $tmp->[1]; push @data, $tmp; } $avg /= @data; my $std = 0; for (@data) { $std += abs($_->[1] - $avg) } $std /= @data; open(OUT, ">pa5c.dat") || die ("Can't open file $!\n"); for (@data) { my $grade; my $dev = ($_->[1] - $avg) / $std; if ($dev >= 1) { $grade = 'A' } elsif ($dev >= (1/3)) { $grade = 'B' } elsif ($dev >= (-1/3)) { $grade = 'C' } elsif ($dev > -1) { $grade = 'D' } else { $grade = 'E' } print OUT join(':', $_->[0], $_->[1], $grade) . "\n"; } close OUT;