Enter your data for 1 Variance

Stat > Basic Statistics > 1 Variance

Specify the data and the null hypothesis for your analysis.

In This Topic

Enter your data
Perform hypothesis test

Enter your data

Select the option that best describes your data.

One or more samples, each in a column

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

Sample standard deviation

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.

Sample variance

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 variance.
Enter the summary statistics in Sample size and Sample variance.

Perform hypothesis test

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 σ²) differs significantly from the hypothesized standard deviation (denoted as σ₀) or the hypothesized variance (denoted as σ²₀) 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 (H₀: σ = σ₀ or H₀: σ² = σ²₀). 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 (H₀: σ = 0.8).