input: from typing import List
  
  def simple_linear_regression(X: List[float], Y: List[float]) -> List[float]:
      """
      Write a code snippet for a simple linear regression model in Python.
      >>> simple_linear_regression([1.0, 2.0, 3.0, 4.0], [2.0, 3.0, 4.0, 5.0])
      [2.0, 3.0, 4.0, 5.0]
      >>> simple_linear_regression([0.0, 1.0, 2.0, 3.0], [0.5, 1.5, 2.5, 3.5])
      [0.5, 1.5, 2.5, 3.5]
      """
output:     n = len(X)
      sum_X = sum(X)
      sum_Y = sum(Y)
      sum_XY = sum([X[i] * Y[i] for i in range(n)])
      sum_X_squared = sum([x ** 2 for x in X])
      
      slope = (n * sum_XY - sum_X * sum_Y) / (n * sum_X_squared - sum_X ** 2)
      intercept = (sum_Y - slope * sum_X) / n
      
      predicted_Y = [slope * x + intercept for x in X]
      
      return predicted_Y