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