# Tag Archives: One categorical variable

## 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 […]

## Hypothesis Test for a Single Proportion

A hypothesis test for a single proportion measures the proportion of a sample taken from the population for a given trait in order to infer information about the proportion of that trait in the whole population itself. The hypothesis test for a single proportion is a test of two contradictory hypotheses about the proportion of the […]

## Pie Charts

A pie chart is a circular graphical display for a single categorical variable. The graph is divided into segments, each representing a particular category. Each segment is the same proportion of a circle as the category is of the total data set. The percentages in the pie chart must add up to 100%. Pie charts […]

## Frequency Tables

A frequency table lists each group of data and the number of occurrences for each category of data. The groups are usually categories (such as car color), intervals (as seen on the right), or values (like number of cars) that will be recorded in the first column. If the classes are numerical, then they need to be […]