my @metrics = (  # Weights don't need to add up to anything specific.
   [ 'Leadership',     0.40 ],
   [ 'Punctuality',    0.20 ],
   [ 'Cleanliness',    0.30 ],
   [ 'Responsiveness', 0.10 ],
);

my @scores = (2, undef, 2, 2);



my $total_weight = 0;

foreach (0..$#metrics) {
   $total_weight += $metrics[$_][1]
      if (defined($scores[$_]));
}



my $total = 0;

foreach (0..$#metrics) {
   if (defined($scores[$_])) {
      my $metric   = $metrics[$_][0];
      my $score    = $scores[$_];
      my $weight   = $metrics[$_][1] / $total_weight;
      my $weighted = $score * $weight;

      $total += $weighted;

      printf("%-20s %d %5.3f %5.3f$/", $metric, $score, $weight, $weig
+hted);
   }
   else
   {
      my $metric = $metrics[$_][0];
      printf("%-20s - ----- -----$/", $metric);
   }
}

printf("%-20s - ----- %5.3f$/", 'Total', $total);

output
======
Leadership           2 0.500 1.000
Punctuality          - ----- -----
Cleanliness          2 0.375 0.750
Responsiveness       2 0.125 0.250
Total                - ----- 2.000
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