MathPHP\Probability\Distribution\Continuous\Pareto::CDF PHP Метод

    public static function CDF($x, $a, $b)
    {
        Support::checkLimits(self::LIMITS, ['x' => $x, 'a' => $a, 'b' => $b]);
        if ($x < $b) {
            return 0;
        }
        return 1 - pow($b / $x, $a);
    }