F-Test in Google Sheets (Step-by-Step)

The F-test is used to determine whether or not two population variances are equal.

The F-test uses the following null and alternative hypotheses:

• H₀: The population variances are equal (σ₁² = σ₂²)
• H_A: The population variances are not equal (σ₁² ≠ σ₂²)

If the p-value of the test is less than some significance level (e.g. α = .05) then we can reject the null hypothesis and conclude that the population variances are not equal.

The following step-by-step example shows how to perform the F-test in Google Sheets.

Step 1: Enter the Data

First, let’s enter the data values for two samples:

Note: The sample sizes do not have to be equal between the two groups to perform the F-test.

Step 2: Perform the F-Test

Next, we will use the =FTEST(sample1, sample2) function to perform the F-test:

The p-value of the test turns out to be .0367.

Since this p-value is less than α = .05, we will reject the null hypothesis.

This means we have sufficient evidence to say that the variances between the two populations that the samples came from are not equal.

Note: The p-value returned by the FTEST() function represents the two-tailed p-value.

Thus, if you were performing a one-tailed test (H_A: σ₁² 2²  or  H_A: σ₁² > σ₂²) then you could simply multiply the resulting p-value by two to get the one-tailed p-value.

Additional Resources

The following tutorials explain how to perform other common tasks in Google Sheets:

How to Perform t-Tests in Google Sheets
How to Calculate Critical Values in Google Sheets
How to Find P-Values in Google Sheets