Capitalize Socialism?

In stratified sampling population is divided into sub-units units. These subpopulations (strata) do not overlap and together form the entire population. From each stratum, a sample, and therefore the final sample will consist of all of these subsamples.

Sample design.

In the population stratified layers , with the sampling design defined in each stratum, independently of the other strata, a sample with probability .

inclusion probabilities.

The inclusion probabilities of first order are , probability of inclusion in the sample if the item is in the stratum .

The inclusion probabilities of the second order are:

• If both units are in : .
• If the unit is in and unity is with : .