Consider the example in the section "Stratified Sampling". The study population is a junior high school with a total of 4,000 students in grades 7, 8, and 9. Researchers want to know how much these ...

Patients in two acute care university hospitals were entered into the study using the following method: twenty patients were selected each day from all floors/units in each hospital until the hospital ...

The authors advocate the use of the generalized variance of the sample means-the determinant of the variance-covariance matrix $D(\overline{y})$ of the means-as a ...

The next sample design for the customer satisfaction survey uses stratification by State. The sampling frame is also sorted by Type and Usage before sample selection, to provide additional control ...

Stratified sampling is used to select a sample that is representative of different groups. If the groups are of different sizes, the number of items selected from each group will be proportional to ...