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