# How can I calculate F critical value in ANOVA method knowing df1, df2 and alpha?

I'm very new to the statistic methods but at the beginning of my wonderful math-journey I found some problems.

Two days ago I got to know the ANOVA method. I'm kind of familiar with it today, but there's one issue that I can not understand.

I know how to calculate F, and df1 so as df2. But how about F critical value? How can I calculate this? (I calculated F, df1, df2, have n, k and alpha given.)

• You do not really calculate it yourself, because it is a quantile of the F-distribution. So you read it off a table (or use a calculator) given your $\alpha$, df1, and df2. – hplieninger Dec 2 '13 at 13:43
• what if I would like to implement it by myself? (I would!) so then, how to calculate it, do I need a big math knowledge? – mazix Dec 2 '13 at 14:08
• There is no closed-form expression for quantiles of the F-distribution. I don't know of any method not involving numeric integration. – Michael M Dec 2 '13 at 14:59
• Yes. As for the normal distribution, probabilities and quantiles can't be found by plugging values in some formula. – Michael M Dec 2 '13 at 21:01
• You can use a statistical package like 'R' (function qf) or relay on tabulated calues as suggested by @hayöpe. An example of such table is given in google.ch/… – Michael M Dec 2 '13 at 21:28