Suppose you're are a contestant in a game show, and the show host tells you there is a car behind one of the three doors you face and a goat behind the other two. You then have to guess which door to open. After you make your guess, the show host (who knows where the car is) opens a different door from the one you chose and reveals a goat. At that point, he gives you the chance to keep your original choice or to choose the other door. Is it advantageous for you to change your guess? *