input: 
  from typing import List
  import numpy as np
  
  def runningTotal(arr: List[float]) -> np.ndarray:
      """ Return an array with the running total of numbers in the given list.
      >>> runningTotal([1, 2, 3, 4])
      array([1, 3, 6, 10])
      >>> runningTotal([0, -1, 1, -2])
      array([0, -1, 0, -2])
      """
      return np.cumsum(arr)
  
output:     return np.cumsum(arr)