1-Sample Z
The 1-Sample Z conducts a hypothesis test of the mean based on sampled data when the population standard deviation, s is known. It also calculates a confidence interval of the mean. This procedure is based on normal distribution. For larger samples (>30), the sample standard deviation may be used in the absence of the population standard deviation. For smaller samples, make sure the data is drawn from a normal distribution or the t-test may be more appropriate.
Test | Null Hypothesis, H0 | Alternate Hypothesis, H1 |
One-tailed | μ = μ0 | μ < μ0 or μ > μ0 |
Two-tailed | μ = μ0 | μ ≠ μ0 |
where μ is the population mean and μ0 is the hypothesised population mean