Think about three samples. If you compute the F-score, and it is close to one, you accept your hypothesis that the samples come from populations with the same variance. The left-tail critical value for x, y degrees of freedom df is simply the inverse of the right-tail table critical value for y, x df.
Rutherford, A. In general, with violations of homogeneity the analysis is considered robust if you have equal sized groups.
In most statistical applications of the F-distribution, only the right tail is of interest, because most applications are testing to see if the variance from a certain source is greater than the variance from another source, so the researcher is interested in finding if the F-score is greater than one.
The ANOVA table breaks down the components of variation in the data into variation between treatments and error or residual variation. While it is not easy to see the extension, the F statistic shown above is a generalization of the test statistic used for testing the equality of exactly two means.
View Wright, D. Quite often, though two hypotheses are really needed for completeness, only Ho is written: Keeping the calculations organized is important when you are finding the variance within.
ANOVA has methods i. She collects data for the number of transactions each day for two months. If the variability in the k comparison groups is not similar, then alternative techniques must be used.