# F-Test

This example teaches you how to perform an **F-Test** in **Excel**. The F-Test is used to test the null hypothesis that the variances of two populations are equal.

Below you can find the study hours of 6 female students and 5 male students.

H_{0}: σ_{1}^{2} = σ_{2}^{2}

H_{1}: σ_{1}^{2} ≠ σ_{2}^{2}

To perform an F-Test, execute the following steps.

1. On the Data tab, in the Analysis group, click Data Analysis.

Note: can't find the Data Analysis button? Click here to load the Analysis ToolPak add-in.

2. Select F-Test Two-Sample for Variances and click OK.

3. Click in the Variable __1__ Range box and select the range A2:A7.

4. Click in the Variable __2__ Range box and select the range B2:B6.

5. Click in the Output Range box and select cell E1.

6. Click OK.

Result:

Important: be sure that the variance of Variable 1 is higher than the variance of Variable 2. This is the case, 160 > 21.7. If not, swap your data. As a result, Excel calculates the correct F value, which is the ratio of Variance 1 to Variance 2 (F = 160 / 21.7 = 7.373).

Conclusion: if F > F Critical one-tail, we reject the null hypothesis. This is the case, 7.373 > 6.256. Therefore, we reject the null hypothesis. The variances of the two populations are unequal.