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    Sample Size

    Sample size is the number of respondents needed for survey results to be statistically meaningful at a given confidence level and margin of error.

    Sample size depends on population size, desired confidence level (typically 95%), and acceptable margin of error (typically ±5%). For a population of 10,000+, a sample of ~370 respondents gives 95% confidence with ±5% margin. Smaller samples yield directional but not statistically robust results.

    Formula

    n = (Z² × p × (1-p)) / E² where Z = z-score, p = expected proportion, E = margin of error

    Example

    For population 10,000, 95% confidence, ±5% margin: n ≈ 370 respondents needed.

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