input: from typing import List
  
  def runningTotal(arr: List[float]) -> List[float]:
      """
      Calculate the running total of numbers in a given list using numpy.
  
      >>> runningTotal([1, 2, 3, 4])
      array([ 1,  3,  6, 10])
      >>> runningTotal([10, -5, 3, 0, 2])
      array([10,  5,  8,  8, 10])
      """
output:     import numpy as np
      return np.cumsum(arr)