Statistics and Probability Dictionary
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Confidence Level
In survey sampling, different samples can be randomly selected from the same population; and
each sample can often produce a different
confidence interval.
Some confidence intervals include the true population parameter; others do not.
A confidence level refers to the percentage of all possible samples
that can be expected to include the true population parameter. For example,
suppose all possible samples were selected from the same population, and a confidence
interval were computed for each sample. A 95% confidence level
implies that 95% of the confidence intervals would include the true population
parameter.