    n = len(list_obj)  
    for x in list_obj:  
        skew += (x - mean_) ** 3  
  
        skew = skew / n if not sample else  n * skew / ((n - 1) * (n - 2))
        SD_ = SD(list_obj, sample)   
        skew = skew / (SD_ ** 3)  
    return skew  
