Chapter 13, Problem 26E

More conclusions In January 2002, two students made worldwide headlines by spinning a Belgian euro 250 times and getting 140 heads—that’s 56%. That makes the 90% confidence interval (51%, 61%). What does this mean? Are these conclusions correct? Explain.

1. a) Between 51% and 61% of all euros are unfair.
2. b) We are 90% sure that in this experiment this euro landed heads on between 51% and 61% of the spins.
3. c) We are 90% sure that spun euros will land heads between 51% and 61% of the time.
4. d) If you spin a euro many times, you can be 90% sure of getting between 51% and 61% heads.
5. e) Ninety percent of all spun euros will land heads between 51% and 61% of the time.