Suppose that the sample of students described in the previous section was actually selected using stratified random sampling. In stratified sampling, the study population is divided into ...

Producers of infant formula employ comprehensive food safety systems, including product testing to ensure those systems are working. A new study from the University of Illinois Urbana-Champaign finds ...

Stratified mean-per-unit sampling is a key tool used by auditors. The popularity of this statistical procedure arises from its unique ability to produce trustworthy ...

This is the description of the sample plan for a survey of enrollments by mail questionnaire of 1800 colleges and universities in the United States. The requirements of the survey included speed, ...