Question

A selection of coin is known to be either fair (with a probability 0.5 of coming up heads or tails when flipped) or biased (with a probability 0.75 of tails, 0.25 of heads.) Further. it is known that 1/10 of the coins are biased. a) You select a coin at random. What are the prior odds (not probability) that you have picked a biased coin? b) You select a coin at random and flip it; you get tails. What are the posterior odds that you have a biased coin? c) Suppose you continue flipping the coin and continue getting tails. How many times must you flip the coin before you believe the coin is more likely to be biased that not?

Answer 1