input: Write a python function that calculates the mean value of the elements in a provided tuple of tuples.
  assert calculate_mean_tuple(((10, 10, 10, 12), (30, 45, 56, 45), (81, 80, 39, 32), (1, 2, 3, 4)))==[30.5, 34.25, 27.0, 23.25]
  assert calculate_mean_tuple(((1, 1, -5), (30, -15, 56), (81, -60, -39), (-10, 2, 3)))== [25.5, -18.0, 3.75]
  assert calculate_mean_tuple( ((100, 100, 100, 120), (300, 450, 560, 450), (810, 800, 390, 320), (10, 20, 30, 40)))==[305.0, 342.5, 270.0, 232.5]
output: def calculate_mean_tuple(list_of_tuples):
      return [sum(x) / len(x) for x in zip(*list_of_tuples)]