input: 
  import numpy as np
  
  def runningTotal(arr):
      """
      This function takes a list of numbers and returns an array with the running total 
      of the numbers.
      
      Example:
      >>> runningTotal([1, 2, 3, 4, 5])
      array([ 1,  3,  6, 10, 15])
      >>> runningTotal([10, 20, 30])
      array([10, 30, 60])
      """
      return np.cumsum(arr)
  
output:     running_total = np.zeros_like(arr)
      running_total[0] = arr[0]
      for i in range(1, len(arr)):
          running_total[i] = running_total[i - 1] + arr[i]
      return running_total