Z-Test Calculator
The Z-test calculator determines if there's a significant difference between sample and population means. It's used in hypothesis testing for quality control, medical research, and social sciences to make data-driven decisions by calculating Z-scores and p-values.
Z-Test Formula
Z = (x̄ - μ) / (σ/√n)
Where:
x̄ = Sample mean
μ = Population mean
σ = Population standard deviation
n = Sample size
How to Use
1. Enter sample mean and population mean 2. Input standard deviation and sample size 3. Set significance level (default 0.05) 4. Click Calculate. The tool will show Z-score, p-value, and hypothesis conclusion. Compare results with critical values table below.
Development Process
1. Designed HTML interface 2. Implemented Z-score formula in JavaScript 3. Added statistical significance calculation 4. Created result display system 5. Integrated user input validation 6. Added critical value table 7. Included FAQ section
Z-Critical Values Table
| Confidence Level | α | Z-Critical |
|---|---|---|
| 90% | 0.10 | ±1.645 |
| 95% | 0.05 | ±1.96 |
| 99% | 0.01 | ±2.576 |