input: 
  def create_model(input_traj: List[float]) -> float:
      """Create a neural network model using TensorFlow to predict the stock price for the next day given a trajectory of stock prices.
      >>> create_model([10, 10.4, 10.5, 10.6, 10.7, 10.9, 11])
      11.1
      """
      import numpy as np
      import tensorflow as tf
  
      model = tf.keras.Sequential([
          tf.keras.layers.Dense(64, activation='relu', input_shape=(7, )),
          tf.keras.layers.Dense(1)
      ])
  
      model.compile(loss='mean_squared_error', 
                    optimizer='adam',
                    metrics=['accuracy'])
  
      input_data = np.array([input_traj])
      predictions = model.predict(input_data)
  
      return predictions[0][0]
  
output:     return predictions[0][0]