Confidence Interval

Most statistical analysis is conducted to reach some conclusion or decision about one or more parameters associated with a population of interest (statistical inference). There are two types of estimators used to assist in reaching a conclusion: point estimators and interval estimators. If the sampling distribution of the point estimator is known, then a likely range of values can be computed for the parameter being estimated. This range is called an interval estimator or confidence interval.

Before proceeding to more detail, here are some terms specific to confidence intervals. Confidence limits or confidence bounds are the upper and lower values of the range for the parameter given by the confidence interval. These limits are obtained from a sample and are random variables. The pivotal quantity is ...