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<?php $frequency = 19; $resultsCount = 319000; $result = (pow($frequency/2, 2) / $resultsCount - (pow($frequency/2, 2) / $resultsCount) * ((0 + 0 + 0)*3 /100)) * 100; var_dump(); var_dump($result);

preferences:
46.15 ms | 402 KiB | 5 Q