Confidence interval

This article needs attention from an expert in statistics. The specific problem is: This article may be too technical for most readers to understand. WikiProject Statistics may be able to help recruit an expert. (April 2025)

In statistics, a confidence interval (CI) is a range of values used to estimate an unknown statistical parameter, such as a population mean.^[1] Rather than reporting a single point estimate (e.g. "the average screen time is 3 hours per day"), a confidence interval provides a range, such as 2 to 4 hours, along with a specified confidence level, typically 95%. This indicates that if the same sampling procedure were repeated 100 times, approximately 95 of the resulting intervals would be expected to contain the true population mean.

A 95% confidence level does not imply a 95% probability that the true parameter lies within a particular calculated interval. The confidence level instead reflects the long-run reliability of the method used to generate the interval.^[2]