input: import numpy as np
  
  def runningTotal(arr):
      """
      Returns an array with the running total of numbers in a given list using numpy.
      >>> runningTotal([1, 2, 3])
      array([1, 3, 6])
      >>> runningTotal([0, -1, 1, 2])
      array([0, -1, 0, 2])
      """
      return np.cumsum(arr)
output:     return np.cumsum(arr)