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

        $returnValue = null;

        $aMean = self::AVERAGEA($aArgs);
        if ($aMean !== null) {
            $aCount = -1;
            foreach ($aArgs as $k => $arg) {
                if ((is_bool($arg)) &&
                    (!Functions::isMatrixValue($k))) {
                } else {
                    // Is it a numeric value?
                    if ((is_numeric($arg)) || (is_bool($arg)) || ((is_string($arg) & ($arg != '')))) {
                        if (is_bool($arg)) {
                            $arg = (int) $arg;
                        } elseif (is_string($arg)) {
                            $arg = 0;
                        }
                        if ($returnValue === null) {
                            $returnValue = pow(($arg - $aMean), 2);
                        } else {
                            $returnValue += pow(($arg - $aMean), 2);
                        }
                        ++$aCount;
                    }
                }
            }

            if (($aCount > 0) && ($returnValue >= 0)) {
                return sqrt($returnValue / $aCount);
            }
        }

        return Functions::DIV0();
    }
public static function STDEVA(...$args)
    {
        $aArgs = Functions::flattenArrayIndexed($args);

        $returnValue = null;

        $aMean = self::AVERAGEA($aArgs);
        if ($aMean !== null) {
            $aCount = -1;
            foreach ($aArgs as $k => $arg) {
                if ((is_bool($arg)) &&
                    (!Functions::isMatrixValue($k))) {
                } else {
                    // Is it a numeric value?
                    if ((is_numeric($arg)) || (is_bool($arg)) || ((is_string($arg) & ($arg != '')))) {
                        if (is_bool($arg)) {
                            $arg = (int) $arg;
                        } elseif (is_string($arg)) {
                            $arg = 0;
                        }
                        if ($returnValue === null) {
                            $returnValue = pow(($arg - $aMean), 2);
                        } else {
                            $returnValue += pow(($arg - $aMean), 2);
                        }
                        ++$aCount;
                    }
                }
            }

            if (($aCount > 0) && ($returnValue >= 0)) {
                return sqrt($returnValue / $aCount);
            }
        }

        return Functions::DIV0();
    }
STDEVA.

Estimates standard deviation based on a sample, including numbers, text, and logical values

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

@category Statistical Functions

@param mixed ...$args Data values

@return float