Confidence Interval for a Proportion
Calculate Confidence Interval for a Proportion instantly with the exact formula and a worked example.
Confidence Interval for a Proportion
p (proportion)
n
z (1.96=95%)
CI half-width
0.098
p
0,5
n
100
Lower
0,402
Upper
0,598
More about: Confidence Interval for a Proportion
What it calculates
The “Confidence Interval for a Proportion” calculator computes CI half-width from 3 parameters: p (proportion), n, z (1.96=95%).
A core calculation for studying, engineering tasks, and checking solutions.
Example calculation
With parameters p (proportion) = 0.5, n = 100, z (1.96=95%) = 1.96 the result is 0.098 (±z·√(p(1−p)/n)).
How to use
- Enter p (proportion), n and z (1.96=95%) — each field above is adjustable with a slider.
- CI half-width is calculated automatically as you type.
- Check the worked example below to see the formula applied to real numbers.
- Copy the result or bookmark this calculator.
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FAQ
How is Confidence Interval for a Proportion calculated?
The Confidence Interval for a Proportion calculator computes CI half-width from p (proportion), n, z (1.96=95%). Enter your values above and the exact formula is applied instantly; a worked example with real numbers is shown below.
Is the Confidence Interval for a Proportion calculator free?
Yes. It is completely free, needs no signup, runs entirely in your browser, and sends no data to any server.
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