# Variance ratio test (F-test)

## Description

The F-test is used to compare the variances of two samples.

## Required input

- For both Sample 1 and Sample 2 select the variable of interest.
- Optionally select filters to include a subset of cases.

## Options

**Logarithmic transformation**: select this option if the data need Logarithmic transformation.

## Results

The results windows for the F-test displays summary statistics of the two samples.

The F-statistic is the ratio of the larger variance over the smaller. If the associated (two-sided) P-value is less than the conventional 0.05, the null hypothesis is rejected and the conclusion is that the two variances do indeed differ significantly.

**Logarithmic transformation**

If you selected the Logarithmic transformation option, the program performs the calculations on the logarithms of the observations, but reports the back-transformed summary statistics.

The variance of the logs cannot be back-transformed meaningfully and therefore the variances and the variance ratio are given on the log-transformed scale.

## See also

## Link

Go to Variance ratio test (F-test).