3v4l.org

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<?php $frequency = 19; $resultsCount = 319000; $result = (pow($frequency/2, 2) / $resultsCount - (pow($frequency/2, 2) / $resultsCount) * ((0 + 0 + 0)*3 /100)) * 100; var_dump($result);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
float(0.028291536050156742)
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33
float(0.028291536050157)

preferences:
249.15 ms | 405 KiB | 313 Q