my %raw_data = (
	1	=>	100,
	2	=>	160,
	2.5	=>	182,
	3	=>	225
	);


my $regr = regression->new(\%raw_data);
print '$regr= ', Dumper($regr);

$mean_x = $regr->get_mean_x;
print '$mean_x= ', Dumper($mean_x);