What is a confidence interval and how does sample size affect its width?

What is a confidence interval and how does sample size affect its width?

• A. A fixed range around the true value that does not depend on data.
• B. A range around an estimate that likely contains the true value; larger sample size yields a narrower interval.
• C. A single point estimate without uncertainty.
• D. A range that expands with more precise measurements.

Answer: (B)