The confidence level of an interval estimate of a parameter

The confidence level of an interval estimate of a parameter is the probability that the interval estimate will contain the parameter.

Solution

A confidence level is the percentage of all possible samples that is expected to include the true population parameter. Suppose all possible samples are selected from the same population, and then a confidence interval has been computed for each sample. Thus a 95% confidence level means that 95% of the confidence intervals would include the true population parameter.