private function buildMedian(Dataset $dataset): self
    {
        $this->median = new Quartile(median(...$dataset->ordinates()));

        return $this;
    }
private function buildMedian(Dataset $dataset): self
    {
        $this->median = new Quartile(median(...$dataset->ordinates()));

        return $this;
    }
private function buildMedian ( Dataset $ dataset ) : self { $ this -> median = new Quartile ( median ( ... $ dataset -> ordinates ( ) ) ) ; return $ this ; }
Extract the median from the dataset

@param Dataset $dataset

@return self
Extract the median from the dataset