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Confidence Intervals
Confidence Interval Calculator
CI for a mean, a proportion, or the difference between two of either.
What are you estimating?
Mean
Proportion
Difference between two means
Difference between two proportions
Confidence level
90%
95%
99%
Custom
Sample mean (x̄)
Sample size (n)
Sample SD (leave σ blank to use this)
Population σ (optional - uses z if given)
Calculate Result