# Sample Tests for a Population Mean

## Small Sample Tests for a Population Mean

### KEY TAKEAWAYS

- There are two formulas for the test statistic in testing hypotheses about a population mean with small samples. One test statistic follows the standard normal distribution, the other Student's -distribution.
- The population standard deviation is used if it is known, otherwise the sample standard deviation is used.
- Either five-step procedure, critical value or -value approach, is used with either test statistic.