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List every defined stratum
Enter the population count and planned positive sample count for each stratum. The included A and B example has counts 750 and 250 with twenty sampled units each. Population coverage and within-group selection remain required design inputs.
Recalculate the population shares
Divide each stratum population count by the population total. The fictional shares are 0.75 and 0.25. If you edit a population count, update the total, shares and contributions rather than leaving the demonstration calculations in place. The CSV stores values and does not automatically recalculate them.
Use the mean and contribution columns
| Stratum | Population share | Sample mean | Contribution |
|---|---|---|---|
| A | 0.75 | 4 | 3 |
| B | 0.25 | 12 | 3 |
| Total | 1 | Not summed | 6 |
Keep estimation and uncertainty separate
The sheet helps organize a mean calculation. It contains no variance estimator or nonresponse adjustment. A group with no usable sample mean needs explicit treatment; entering zero would manufacture an observation. Retain actual group definitions alongside the file.