Definition
- A confidence interval is a range of values, derived from sample data, that is likely to contain the true population parameter. It is associated with a confidence level, such as 95%, indicating the probability that the interval captures the true parameter.
Key Points
- Confidence Level: The likelihood that the interval includes the true parameter (e.g., 95%).
- Purpose: Quantifies the uncertainty of an estimate, providing a range rather than a single value.
Example
- A 95% confidence interval for a mean of (50, 60) suggests that, in repeated sampling, 95% of such intervals would contain the true mean.