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

        // Return value
        $returnValue = null;

        $aMean = self::AVERAGE($aArgs);
        if ($aMean != Functions::DIV0()) {
            $aCount = -1;
            foreach ($aArgs as $k => $arg) {
                // Is it a numeric value?
                if ((is_bool($arg)) &&
                    ((!Functions::isCellValue($k)) ||
                    (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE))) {
                    $arg = (int) $arg;
                }
                if ((is_numeric($arg)) && (!is_string($arg))) {
                    if ($returnValue === null) {
                        $returnValue = pow(($arg - $aMean), 2);
                    } else {
                        $returnValue += pow(($arg - $aMean), 2);
                    }
                    ++$aCount;
                }
            }

            // Return
            if ($returnValue === null) {
                return Functions::NAN();
            }

            return $returnValue;
        }

        return self::NA();
    }
public static function DEVSQ(...$args)
    {
        $aArgs = Functions::flattenArrayIndexed($args);

        // Return value
        $returnValue = null;

        $aMean = self::AVERAGE($aArgs);
        if ($aMean != Functions::DIV0()) {
            $aCount = -1;
            foreach ($aArgs as $k => $arg) {
                // Is it a numeric value?
                if ((is_bool($arg)) &&
                    ((!Functions::isCellValue($k)) ||
                    (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE))) {
                    $arg = (int) $arg;
                }
                if ((is_numeric($arg)) && (!is_string($arg))) {
                    if ($returnValue === null) {
                        $returnValue = pow(($arg - $aMean), 2);
                    } else {
                        $returnValue += pow(($arg - $aMean), 2);
                    }
                    ++$aCount;
                }
            }

            // Return
            if ($returnValue === null) {
                return Functions::NAN();
            }

            return $returnValue;
        }

        return self::NA();
    }
DEVSQ.

Returns the sum of squares of deviations of data points from their sample mean.

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

@category Statistical Functions

@param mixed ...$args Data values

@return float