Results for this study are based on telephone interviews conducted by Social Science Research Solutions (SSRS), an independent research company, among a nationally representative sample of 1,220 ...

Survey data in this report are based on Pew Research Center surveys conducted with a nationally representative sample of Hispanics. Differences between groups or subgroups, such as foreign-born and ...

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 ...

In a stratified sample, it is possible that some strata will have only one sampling unit. When this happens, PROC SURVEYREG collapses these strata that contain single sampling unit into a pooled ...

Mary Hall is a editor for Investopedia's Advisor Insights, in addition to being the editor of several books and doctoral papers. Mary received her bachelor's in English from Kent State University with ...

Figure 1: Summary of the two series of analyses performed in this study. We found that the extent of social stratification, as well as the presence of human sacrifice, varied throughout a wide range ...