input: from typing import List
  
  def runningTotal(arr: List[int]) -> List[int]:
      """ Returns an array with the running total of numbers in a given list.
      >>> runningTotal([1, 2, 3, 4])
      array([1, 3, 6, 10])
      >>> runningTotal([10, 20, 30])
      array([10, 30, 60])
      """
      return np.cumsum(arr)
output:     running_total = []
      current_sum = 0
      for num in arr:
          current_sum += num
          running_total.append(current_sum)
      return running_total