Confidence Interval Calculator | Z-Interval & T-Interval
Calculate confidence intervals for population means and proportions. Compares Wald and Wilson Score models with dynamic critical value solvers.
Sample Statistics
Solved Confidence Interval (95% Confidence)
[95.7361, 104.2639]
Point Estimate: 100.0000 ± 4.2639 (Margin of Error)
Critical T*2.0100
Standard Error2.12132
Sample Size (n)50
Confidence Interval Axis Map
95.736Lower
100.000Point
104.264Upper
Step-by-Step Statistical Calculations
11. Selected T-Interval (estimated sample standard deviation s = 15).
22. Solved Degrees of Freedom: df = n - 1 = 50 - 1 = 49
33. Solved T* critical value for df = 49 and Confidence Level = 95%: T* = 2.01
44. Calculated Standard Error (SE) = s / √n = 15 / √50 = 2.12132
55. Calculated Margin of Error (E) = T* * SE = 2.01 * 2.12132 = 4.26385
66. Constructed interval bounds = mean ± E = 100 ± 4.26385
7 Interval lower/upper limits: [95.7361, 104.2639]