input: Write a python function to calculate the average of a list of 10 numbers provided by the user.
  assert calculate_average([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == 5.5
  assert calculate_average([10, 20, 30, 40, 50, 60, 70, 80, 90, 100]) == 55.0
  assert calculate_average([5, 15, 25, 35, 45, 55, 65, 75, 85, 95]) == 50.0
output: def calculate_average(numbers):
      return sum(numbers) / len(numbers)