my $median_class_avg;    #-- median class average
...
#-- Open the input file 
open(INPUT, '<', $input_file) or die "Couldn't open $input_file: $!\n";
...
   #-- Print student's average
   printf "%5.1f%2s", $students{$name}{avg_grade};

##</code><code>##

   foreach ( 0 .. $#{ $students{$name}{grades} } )
   {
      printf "%4d", $students{$name}{grades}[$_];
   }

##</code><code>##

  foreach $grade (@{$students{$name}{grades}}) {
    printf "%4d", $grade;
  }

##</code><code>##

  my @grades = $students{$name}{grades};
  foreach my $grade (@grades) {
    printf "%4d", $grade;
  }