$some_pos = 950;  
print +( $_->[1] < $_->[0] and $_->[1] >= $some_pos ) 
    ? 'contained' 
    : 'not contained' for [0, 901];;
not contained

##</code><code>##

sub variance {
  my $self = shift;  ##Myself
  my $div = @_ ? 0 : 1;
...
    $variance /= $count - $div;

##</code><code>##

[21:59:37.22] C:\test>874353
 10000: 10.003  9.138
10.0028 9.13839215999999

[21:59:44.34] C:\test>874353
 10000: 10.003  9.139
10.0028 9.13930609060905