Written by the Fiveable Content Team โข Last updated September 2025
Written by the Fiveable Content Team โข Last updated September 2025
Definition
The F distribution is a continuous probability distribution that arises frequently as the null distribution of a test statistic, especially in ANOVA. It is defined by two parameters: the degrees of freedom for the numerator and the denominator.
5 Must Know Facts For Your Next Test
The F distribution is used to compare variances between groups.
It is asymmetric and skewed to the right, becoming more symmetric as sample sizes increase.
Degrees of freedom for the numerator come from the number of groups minus one, while degrees of freedom for the denominator come from total observations minus number of groups.
The critical values for an F-test are found using F-tables or statistical software.
In ANOVA, a high F-ratio suggests that at least one group mean is different from others.
Analysis of Variance (ANOVA) is a statistical method used to compare means across multiple groups to determine if at least one group mean differs significantly.
F-Ratio: The F-Ratio is a test statistic calculated as the ratio of variance between group means to variance within groups.