1-Sample Z-Test
Test whether a population mean equals a hypothesised value when the population standard deviation is known.
Data Input
When to Use
Use the 1-Sample Z-Test when you know the population standard deviation (σ) and want to test whether the population mean equals a specific value. This is common in Measure phase when historical process data provides a reliable σ estimate.
If σ is unknown, use the 1-Sample t-Test instead. The Z-test is most reliable for n ≥ 30 or when the population is known to be normal.