input: Write a python function to calculate the average of a list of temperatures.
  assert get_average([22.5, 18.7, 30.1]) == 23.766666666666666
  assert get_average([10.0, 20.0, 30.0, 40.0]) == 25.0
  assert get_average([5.5, 5.5, 5.5, 5.5]) == 5.5
output: def get_average(temperatures):
      return sum(temperatures) / len(temperatures)