Updating with simulation

We see 11 out of 20 flips from a coin that is either fair (50% chance of heads) or biased (75% chance of heads). How likely is it that the coin is fair? Answer this by simulating 50,000 fair coins and 50,000 biased coins.

Simulate 50,000 cases of flipping 20 coins from a fair coin (50% chance of heads), as well as from a biased coin (75% chance of heads). Save these variables as fair and biased respectively.
Find the number of fair coins where exactly 11/20 came up heads, then the number of biased coins where exactly 11/20 came up heads. Save them as fair_11 and biased_11 respectively.
Find the fraction of all coins that came up heads 11 times that were fair coins- this is the posterior probability that a coin with 11/20 is fair.

Take Hint (-30 XP)

Exercise

Updating with simulation

Instructions