input: Write a python function to create a simple quiz with predefined questions and answers stored in a dictionary.
  assert 'quiz_questions' in globals() and isinstance(quiz_questions, dict)
  assert 'Paris' in quiz_questions.values()
  assert callable(quiz)
output: def quiz():
      quiz_questions = {
          "What is the capital of France?": "Paris",
          "What is 2 + 2?": "4",
          "What color is the sky on a clear day?": "Blue"
      }
      
      score = 0
      for question, answer in quiz_questions.items():
          user_answer = input(question + " ")
          if user_answer.lower() == answer.lower():
              score += 1
              print("Correct!")
          else:
              print(f"Wrong! The correct answer is {answer}.")
      
      print(f"Your final score is {score}/{len(quiz_questions)}")