# Enter your data for 1 Variance

Stat > Basic Statistics > 1 Variance

Specify the data and the null hypothesis for your analysis.

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.

1. From the drop-down list, select One or more samples, each in a column.
2. 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.

1. From the drop-down list, select Sample standard deviation.
2. 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.

1. From the drop-down list, select Sample variance.
2. 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.
1. 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?.
2. 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).