#!/usr/bin/perl -w
       use strict;
       
       
       $my infile = shift;
       $my outfile = shift;
       
       open(IN, $infile) || die("Can't open input file $infile - $!");
       open(OUT, ">$outfile") || die("Can't open output file $outfile - $!");

              my $text;
       my $text2;
       my @lines;
      
       while (<IN>) {
         push @lines;
         shift @lines if @lines > 10;
       }

       chomp(@lines);

       my @cols;
       my $total = 0;

       for (@lines) {
         @cols = split /:/;
        print "($cols[3]) $_";
         $total += $cols[3];
       }
       my $average = $total / (@lines || 1);
       

                # if no lines, avoid division by zero
         
          my $last = (split /:/, $lines[-1])[3];

       
 $text = "Average of column 3 for the last " .
                              scalar(@lines) . " days: $average\n";       
  $text2 ="Last value in Col3 " . 
                              scalar(@lines) . "  $last\n";

      print OUT "$text\n";
      print OUT "$text2\n";

	
       close IN;
       close OUT ;