input: from typing import List
  
  def runningTotal(arr: List[int]) -> List[int]:
      """
      Calculate the running total of numbers in a given list using numpy.
      >>> runningTotal([1, 2, 3, 4])
      [1, 3, 6, 10]
      >>> runningTotal([5, -1, 2, 0])
      [5, 4, 6, 6]
      """
output:     import numpy as np
      return np.cumsum(arr).tolist()