Confidence intervals for a population mean

What this note covers

1. From an observed average to an interval estimate
2. A complete known-sigma calculation
3. Confidence is long-run coverage of a procedure
4. Confidence level and sample size change width
5. Planning a sample size for a target margin
6. Assessing a claimed mean without claiming proof
7. Recovering design choices from an interval
8. Comparing two precision plans

8 sections · 10 key terms & formulas · 6 common mistakes