Students at a science fair conducted an experiment to determine whether the Belgium-minted Euro coin was equally likely to land heads up or tails up. Coins were spun on a smooth surface, and in 240 spins, 130 landed with the heads side up. Should the students interpret this result as convincing evidence that the coin is not fair (proportion heads up is not 0.5)? Answer the following.
1. What is the sample proportion? Define the parameter that is approximated by the sample proportion.
2. State and verify that the conditions for a confidence interval in this setting are met.
3. Calculate the 95% confidence interval. Show work.
4. Interpret the interval that you found in question 3.
5. Use the result of question 4 to determine whether the coin is a fair coin.