Specify the data and the null hypothesis for your analysis.

Select the option that best describes your data.

Complete the following steps if your data are in a column of the worksheet:
###### Note

When you enter a column of data, Minitab only calculates a confidence interval for the standard deviation. However, you can still perform a hypothesis test for the standard deviation or the variance.

- From the drop-down list, select One or more samples, each in a column.
- Enter the column of data that you want to analyze.
###### Tip

Click in the empty field under the drop-down list to see the data columns that are available for your analysis.

In this worksheet, Length indicates the length of beams that are cut at a saw mill.

C1 |
---|

Length |

99.002 |

100.242 |

100.042 |

99.596 |

Complete the following steps if you have summary statistics for the sample, rather than actual sample data in the worksheet.

- From the drop-down list, select Sample standard deviation.
- Enter the summary statistics in Sample size and Sample standard deviation.

- From the drop-down list, select Sample variance.
- Enter the summary statistics in Sample size and Sample variance.

If you want to calculate a p-value to determine whether the mean differs from a hypothesized mean, you must perform a hypothesis test.

- Use a hypothesis test to determine whether the population standard deviation (denoted as σ) or population variance (denoted as σ
^{2}) differs significantly from the hypothesized standard deviation (denoted as σ_{0}) or the hypothesized variance (denoted as σ^{2}_{0}) that you specify. If you don't perform the test, Minitab still displays a confidence interval, which is a range of values that is likely to include the population standard deviation or population variance. For more information, go to What is a hypothesis test?. - The Hypothesized standard deviation or Hypothesized variance defines your null hypothesis (H
_{0}: σ = σ_{0}or H_{0}: σ^{2}= σ^{2}_{0}). Think of this value as a target value or a reference value. For example, an engineer enters 0.8 to determine whether the standard deviation of pipe diameters is different from 0.8 mm (H_{0}: σ = 0.8).