How do I calculate sample size for stratified sampling?

How do I calculate sample size for stratified sampling?

To calculate sample size for stratified sampling, you need to determine the population size, the number of strata, and the desired confidence level.

What formula should I use for this calculation?

You can use the formula: n = (N * Z^2 * p * (1-p)) / (E^2 * (N-1) + Z^2 * p * (1-p)), where n is the sample size, N is the population size, Z is the Z-score, p is the estimated proportion, and E is the margin of error.

Can you explain what Z-score and margin of error mean?

The Z-score corresponds to the confidence level you want (e.g., 1.96 for 95% confidence), and the margin of error is the range within which you expect the true population parameter to fall.

How do I determine the number of strata?

The number of strata should be based on the characteristics of the population. You can stratify by factors like age, income, or education level to ensure representation.