Confidence Interval Calculator
Calculate confidence intervals for population mean
Results:
95% Confidence Interval:
[94.6323, 105.3677]
Sample Mean: 100.0000
Margin of Error: ± 5.3677
Standard Error: 2.7386
Z-Score: 1.96
Sample Size: 30
About Confidence Intervals
A confidence interval gives a range of values that likely contains the true population parameter.
Formula: CI = x̄ ± z(σ/√n)
Where:
- x̄ = sample mean
- z = z-score for confidence level
- σ = standard deviation
- n = sample size
A 95% CI means we are 95% confident the true population mean falls within this interval.