input: import numpy as np
  
  def runningTotal(arr):
      """ Returns an array with the running total of numbers in a given list.
      >>> runningTotal([1, 2, 3, 4])
      array([1, 3, 6, 10])
      >>> runningTotal([5, 4.5, -1.5, 0])
      array([5. , 9.5, 8. , 8. ])
      """
      return np.cumsum(arr)
output:     return np.cumsum(arr)