my %vals_by_type;
while (<DATA>) {
    chomp;
    my ($type, $val) = split ' ';
    push @{ $vals_by_type{$type} }, $val;
}

##</code><code>##

use List::Util qw( sum );

for my $type (sort keys %vals_by_type) {
    my $vals = $vals_by_type{$type};
    my $avg = sum( map $_/@$vals, @$vals );
    printf("%s %.2f\n", $type, $avg);
}