Confidence interval calculator. The math is in C, compiled to WebAssembly, with a SolidJS interface.
Formulas
Margin of error for the mean:
E = z · s / √n
Finite population correction, applied when n/N > 0.05:
E = z · (s / √n) · √((N − n) / (N − 1))
Confidence interval:
x̄ − E ≤ μ ≤ x̄ + E
Margin of error for a proportion:
E = z · √(p̂(1 − p̂) / n)
With finite population correction, applied when n/N > 0.05:
E = z · √(p̂(1 − p̂) / n) · √((N − n) / (N − 1))
Confidence interval:
p̂ − E ≤ p ≤ p̂ + E