R Tutorial: Monty Hall

Want to learn more? Take the full course at https://learn.datacamp.com/courses/probability-puzzles-in-r at your own pace. More than a video, you'll learn hands-on coding & quickly apply skills to your daily work. --- Another well-known probability puzzle is Monty Hall, which is named after the host of a game show called Let's Make a Deal. In this puzzle, a contestant is shown three doors. Behind one of the doors is a prize, and the other two doors contain no prize. Historically, the prize was a car and the non-prizes were goats. The game begins with the contestant picking a door. Suppose that the contestant has chosen Door number 1. The host, Monty Hall, then opens one of the other doors that does not contain the prize. The contestant has a choice, to stick or switch? To stick means to stay with the original choice, here Door number 1, and to switch means to choose the remaining door, here Door number 3. Which strategy gives the greatest probability of winning the prize, and what are the probabilities with each strategy? A common misconception is that sticking or switching both give a 50 50 chance of winning since there are only two remaining doors. In this puzzle, we will write code to simulate both strategies to demonstrate the true win probability in each case. To solve this problem, we need to handle some R indexing, specifically when determining which door the host should reveal. Consider the doors object, which contains the values 1, 2, and 3, to represent each door. If the contestant chooses door number 1, and the prize is behind door number 2, then the only possible door that the host can reveal is door number 3. From a coding standpoint, we must exclude doors 1 and 2 from the possibilities of doors to reveal. We can do this by using a minus index with the c concatenator to remove doors 1 and 2 as possibilities. Then, the value of the reveal is only door number 3. Note that, in general, we can reference elements of the doors object by supplying e