input: from typing import List
  
  
  def mean_absolute_deviation(numbers: List[float]) -> float:
      """ For a given list of input numbers, calculate Mean Absolute Deviation
      around the mean of this dataset.
      Mean Absolute Deviation is the average absolute difference between each
      element and a centerpoint (mean in this case):
      MAD = average | x - x_mean |
      >>> mean_absolute_deviation([1.0, 2.0, 3.0, 4.0])
      1.0
      """
  
output:     mean_value = sum(numbers) / len(numbers)
      absolute_deviations = [abs(x - mean_value) for x in numbers]
      return sum(absolute_deviations) / len(numbers)