Mean Confidence Interval Calculator
Two-sided Z interval with known population deviation and a normal population or sufficiently large sample.
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Two-sided Z interval with known population deviation and a normal population or sufficiently large sample.
Worked example
Inputs
- Sample mean: 100
- Population standard deviation: 15
- Sample size: 100
- Confidence level: 95%
Results
- Lower bound: 97.06005402
- Upper bound: 102.939946
- Margin of error: 2.939945977
Two-sided Z interval with known population deviation and a normal population or sufficiently large sample.
Reviewed:Common uses
Two-sided Z interval with known population deviation and a normal population or sufficiently large sample.
BEHIND THE NUMBERSFormula & assumptions
CI=x̄±zσ/√n
Two-sided Z interval with known population deviation and a normal population or sufficiently large sample.