This edition: Inference for Proportions
This lesson returns to the topic of proportions, applying what you have learned about confidence intervals, margins of error, and tests of significance to this type of data. As you may recall, instead of examining a quantitative value like the population mean, researchers often want to examine a categorical value, such as the proportion of a sample group that meets a certain criterion. For instance, they might want to study what proportion of voters intend to cast their ballots for a certain candidate of interest, or what proportion of students in an incoming college class are of a certain ethnic background. The answers generated by these questions are often expressed in terms of percentages, since a percentage is a proportion.