Everything else is ready: study the parts, the key terms and the quiz below.
Confidence Intervals
Report an estimate with its uncertainty, and say what the interval does and does not mean.
In this lesson6 parts
- 01Decide what one sample can tell us
- 02Draw and summarize one sample
- 03Build the interval before deciding
- 04Check repeated-sample coverage against the archive
- 05A mean interval has different assumptions
- 06Reproduce and explain the decision
Key terms
The words this lesson introduces, each in one line. The module’s glossary collects them all.
- cancellation record
- An invoice ID with a C prefix; refund status is not established.
- threshold
- A predeclared value used for this review decision.
- point estimate
- One statistic computed from one sample.
- confidence interval
- Bounds produced by a sampling procedure.
- Wilson confidence interval
- A score-based interval for a binary share.
- confidence level
- The intended long-run coverage of a procedure under its assumptions.
- coverage
- Fraction of repeated intervals containing a fixed target.
- sample mean
- Sum of sampled numeric values divided by sample size.
- t interval
- A mean interval using sample spread and a t cutoff; its coverage depends on approximation conditions.
Quiz 5 questions
Your first pick on each question is the one that counts, and a right one earns a coin. Getting one wrong here is how the lesson sticks.
Practice
Problems to solve in your own notebook. Each states the problem, not the steps: working out the steps is the exercise. Level A applies the lesson, B combines it with earlier ones, C stretches it.
The self-checking notebook for this lesson is Stats 5.1 and 5.3 · Sampling distributions and confidence intervals.
Common mistakes
What you will see when it goes wrong, why it happens, and the fix.
Where it’s used
Where this lesson’s ideas turn up in real work.