:type start: int
        :type limit: int
        :type mean: int
        :rtype: list()

def deviation(self, series, start, limit, mean):
        '''
        :type start: int
        :type limit: int
        :type mean: int
        :rtype: list()
        '''
        d = []
        for x in range(start, limit):
            d.append(float(series[x] - mean))
        return d