Statistics & Probability
95% Confidence Interval
Approximate 95% CI for the mean (z = 1.96).
Formula
Formula
x̄ ± 1.96 · s√n
Variables
| Symbol | Definition | Type & range | Units | Role |
|---|---|---|---|---|
| x̄ | sample mean | computed result | — | result |
| s | sample std | computed result | — | result |
| n | sample size | computed result | — | result |
Try it yourself
Interactive calculator
Worked examples
Example 1
Givendata = 4, 8, 15, 16, 23, 42
Result
lower
7.205161727
upper
28.79483827
Example 2
Givendata = 50, 52, 48, 51, 49
Result
lower
48.61407071
upper
51.38592929