use List::Util qw(sum);
my $total = sum values %$group;

my $rnd = rand( $total );
my $runningtot = 0;

foreach ( keys %$group ) {
    
    if ( $rnd > $runningtot && $rnd <= ( $runningtot + $group->{$_} ) ) {
        $picked = $_;
        last;
    }#if

    $runningtot += $group->{$_};

}#foreach