Billy plays darts. He assumes that each dart throw is independent and he knows from past experience that the probability of hitting the bullseye is 0.2
Billy throws 9 darts. Calculate the probability that at least 3 of the darts will hit the bullseye.
Billy believes he has improved and the chance of hitting the bullseye is greater than 0.2. He throws 20 darts and 6 hit the bullseye. Stating your hypotheses clearly test, at the 5% level of significance, whether or not there is evidence to support Billy's belief.