Two Means Confidence Interval Calculator
Easily calculate the confidence interval for the difference between two population means. Input sample data and confidence level for instant results.
Sample Group 1
Sample Group 2
Results
Confidence Interval: (, )
Visualization of Confidence Interval
Scale: Difference of Means
Understanding Confidence Intervals for Two Means
A confidence interval for the difference between two means estimates the range within which the true difference between the population means is likely to fall. This calculator is specifically for independent samples where the population standard deviations are unknown but assumed to be equal.
It uses the t-distribution and pooled standard deviation to account for the uncertainty introduced by estimating the population standard deviation from sample data. The inputs required are the sample means (x̄1, x̄2), sample sizes (n1, n2), sample standard deviations (s1, s2), and the desired confidence level.
The output is the confidence interval, presented as a lower and upper bound. This interval provides a range of plausible values for the difference between the two population means.