20.5 Interpretation of a CI

The correct interpretation (Definition 20.3) of a 95% CI is the following:

If samples were repeatedly taken many times, and the 95% confidence interval computed for each sample, 95% of these confidence intervals formed would contain the population parameter.

However, most people would think of our 95% CI as having a 95% chance of containing the value of population parameter \(p\). This is not strictly correct (our CI either does or does not contain the value of \(p\)), but is common.

More details on interpreting a CI are given in Sect. 21.2.