Suppose you create a 95% confidence interval for a mean, and get (-2.346, 8.775). You've been told to report this by saying, "We are 95% confident that the true mean is between -2.346 and 8.775." Exactly what does this mean?
1. There is a 95% chance that the true mean is between -2.346 and 8.775.
2. 95% of all 95% confidence intervals actually contain the true mean.
3. 95% of the data are between -2.346 and 8.775.
4. 95% of the sample means are between -2.346 and 8.775.