Why Laravel gives wrong result query?

$groups = Groups::-where("min", '>=', $result->Z)->where("max", '<=', $result->Z)->orderBy('min')->get();

Where $result->Z is 52.850294770880225.

So, I should get row:

4 | 47.01 | 52.99 | 0

Instead this:

7 | 55.01 | NULL | 1

via Chebli Mohamed