What is the Hypothesis Testing (Z-test) Calculator?

The Hypothesis Testing Calculator allows you to perform a Z-test to determine whether there is enough evidence to reject a null hypothesis (H₀) based on your sample data. By inputting the sample mean, population mean, population standard deviation, sample size, and test type, the calculator computes the Z-statistic and provides the decision criteria for rejecting or failing to reject H₀. This tool is useful for students, researchers, and data analysts working on statistical tests, quality control, or research studies.

How to Use:

1. Enter Sample Mean (x̄): Type the mean value of your sample data.
2. Enter Population Mean (μ): Type the known or hypothesized population mean.
3. Enter Population Standard Deviation (σ): Input the standard deviation of the population.
4. Enter Sample Size (n): Input the number of observations in your sample.
5. Select Test Type: Choose Two-tailed, Left-tailed, or Right-tailed based on your hypothesis.
6. Click “Calculate”: The calculator computes the Z-statistic and shows the decision rule for rejecting the null hypothesis.
7. Review the Result: Use the Z-value and decision guideline to interpret whether your sample provides significant evidence against H₀.