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Margin of Error Calculator
The plus-or-minus on a survey result, from the sample size and the share who answered.
Result…
How it's calculated
MOE = z × √( p(1 − p) ÷ n ) × √((N − n) ÷ (N − 1)) for a finite population
A poll of 1,000 people at 50% has a margin of about ±3.1 points at 95% confidence. The margin covers random sampling error only; a biased sample, a leading question or low response rates can add far more error than this. It assumes a simple random sample.
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