Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Calculation/Statistical.php
public static function GEOMEAN(...$args)
    {
        $aArgs = Functions::flattenArray($args);

        $aMean = MathTrig::PRODUCT($aArgs);
        if (is_numeric($aMean) && ($aMean > 0)) {
            $aCount = self::COUNT($aArgs);
            if (self::MIN($aArgs) > 0) {
                return pow($aMean, (1 / $aCount));
            }
        }

        return Functions::NAN();
    }
public static function GEOMEAN(...$args)
    {
        $aArgs = Functions::flattenArray($args);

        $aMean = MathTrig::PRODUCT($aArgs);
        if (is_numeric($aMean) && ($aMean > 0)) {
            $aCount = self::COUNT($aArgs);
            if (self::MIN($aArgs) > 0) {
                return pow($aMean, (1 / $aCount));
            }
        }

        return Functions::NAN();
    }
GEOMEAN.

Returns the geometric mean of an array or range of positive data. For example, you
can use GEOMEAN to calculate average growth rate given compound interest with
variable rates.

Excel Function:
GEOMEAN(value1[,value2[, ...]])

@category Statistical Functions

@param mixed ...$args Data values

@return float