input: 
  def predict_house_price(features: np.ndarray, model: Sequential) -> float:
      """ Predict the price of a house using a pre-trained neural network model.
      The model should be trained to take a set of features as input and output a 
      single price prediction.
      >>> predict_house_price(np.array([[0.8, 0.4, 0.7]]), model)
      120000.0
      """
  
output:     prediction = model.predict(features)
      return float(prediction[0][0])