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Sample Size Calculator for a Proportion

This calculator determines the sample size for a population proportion from confidence level and desired margin of error.

Leave it as 0.5 if you are unsure.

Sample Size Calculator for a Mean

How to Use Sample Size Calculator for a Proportion?

  1. First, input the confidence level and desired margin of error.
  2. Input the expected proportion. Leave it as 0.5 if it's unknown.
  3. Press the 'Calculate' button to obtain the sample size result.

How to Calculate?

The following formula is used to calculate the sample size required for a population proportion.

Sample Size (s) = p × (1-p) × (Zα/2 / E)2

Where,
p = Expected proportion,
Zα/2 = Z-value associated with the confidence level,
E = Desired margin of error.

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