The Syntax Stratified LargeCap ETF (ticker: SSPY) holds the same companies as the S&P 500 but reweights them using a Stratified-Weight methodology. By using the S&P 500 and weighting these companies ...

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 ...

A straightforward procedure is presented which uses the variance formula of a simple estimator to obtain an approximate formula for the variance of a post-stratified estimator. The approximation is ...

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 ...

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 ...