input: from typing import List
  
  
  def mad(numbers: List[float]) -> float:
      """ For the provided list of floats, compute the Mean Absolute Deviation (MAD),
      which is the average of the absolute differences between each element and the 
      mean value of the list.
      MAD = average | x - mean(x) |
      >>> mad([1.0, 2.0, 3.0, 4.0])
      1.0
      """
output:     mean_value = sum(numbers) / len(numbers)
      deviations = [abs(x - mean_value) for x in numbers]
      return sum(deviations) / len(deviations)