- Use x-bar to estimate the population mean, μ.
- Understand the logic of a confidence interval: why a range of values can be predicted at a given level of confidence based on its sampling distribution and the Central Limit Theorem.
- Understand that the error in a confidence interval only accounts for randomness in sampling, not for undercoverage or nonresponse.
- Find a confidence interval for a sample mean with a known σ using normal curves.
This connects back to the baseline of how confident we are that a value is within a given distance of the mean.