A confidence interval is a type of interval estimate of a population parameter and is used to indicate the reliability of an estimate.
For users of frequentist methods, various interpretations of a confidence interval can be given.
Readers of polls, such as the Gallup Poll, should exercise Caveat Emptor by taking into account the poll's margin of error.
The proportion of confidence intervals that contain the true value of a parameter will match the confidence level.
A major factor determining the length of a confidence interval is the size of the sample used in the estimation procedure.
The procedure to find the confidence interval and the confidence level for a proportion is similar to that for the population mean.
In this section, we outline an example of finding the confidence interval for a population mean when we know the standard deviation.
In this section, we outline an example of finding the confidence interval for a population mean when we do not know the standard deviation.
The chi-square distribution is used to construct confidence intervals for a population variance.