# Category Confidence Intervals

## Confidence interval for a single proportion

A confidence interval gives an estimated range of values which is likely to include an unknown population parameter, the estimated range being calculated from a given set of sample data, as this site puts it. This site says statisticians use a confidence interval to describe the amount of uncertainty associated with a sample estimate of a population parameter. They are used […]

## Confidence interval for two independent means

A confidence interval for two independent means is a method of statistical inference to determine if there is a difference between the mean values of two populations, or what the value of the difference may be. Since it compares two populations, there must be a (binary) categorical variable involved in the global population by which to […]

## Confidence Interval for Two Independent Proportions

A confidence interval for two independent proportions is a tool used in inferential statistics to estimate a proportional* difference between two independent populations. These two populations must be distinguished by a single binary categorical variable; e.g. sex (male or female), but not blood type (A, B, AB, or O). With this information, it can be […]

## Confidence Interval for a Single Mean

A confidence interval for a single mean, specifically, is just a regular confidence interval that tries to estimate the possible mean of the population. Stattrek explains a confidence interval as “…to describe the amount of uncertainty associated with a sample estimate of a population parameter.”It’s not exact, and the higher percentage of confidence you want, the bigger the […]

## Confidence Interval for Two Independent Means

A confidence interval for two independent means is calculated to likely contain the difference between two true population means for one binary categorical variable and one quantitative variable. For example, a company might be considering replacing some of its packaging workers with machines, so they will compare the mean amount of time it takes a […]

## Confidence Interval for Paired Means

The testing method of paired means is used to compare the means of two variables for a single group. It is often referred to as the paired difference test since it tests whether the difference between two variables within the single group. It is important to note that since the data is “paired” it is not independent. […]

## Confidence Interval for Two Independent Proportions

Confidence interval for two independent proportions gives an estimated range of values, which is likely to include the difference between the two true population proportions for two categorical variables. For example, medical researchers may want to compare the proportions of men and women who suffered from heart attacks. The procedure for obtaining such an interval […]