Is the euro fair? Soon after the euro was introduced as currency in Europe, it was widely reported that someone had spun a euro coin 250 times and gotten heads 140 times. We wish to test a hypothesis about the fairness of spinning the coin.

a) Estimate the true proportion of heads. Use a 95% confidence interval. Don’t forget to check the conditions.

b) Does your confidence interval provide evidence that the coin is unfair when spun? Explain.

c) What is the significance level of this test? Explain.