input: Write a function called calculate_average that takes no input and calculates the average of five numbers entered by the user. The function should return the calculated average. 
  
  assert calculate_average() == 3.0  # Assuming user inputs 1, 2, 3, 4, 5
  assert calculate_average() == 7.4  # Assuming user inputs 6, 8, 7, 9, 5
output: def calculate_average():
      total = 0
      for i in range(5):
          total += float(input())
      return total / 5