# Calculating P- value

In ANOVA table , I got

$$F$$-statistic $$=330.285$$

degrees of freedom (df) due to regression $$= 6$$

Error degrees of freedom $$= 9$$

But i don't know how to calculate $$p-$$value ?

I have tried in R software as

pf ( 330.285, 6, 9, lower.tail = F )

[1] 1

But it doesn't match with the result which is actually .000

Where am i doing mistake ?

I tried the command you stated and got

> pf( 330.285, 2, 26, lower.tail = F )
[1] 3.294207e-19

which is very close to the value you are expecting.

• Please, see the edit . I've wrote wrong df in the first post.
– ABC
Commented Apr 11, 2015 at 1:34
• But also i am getting 1 in pf( 330.285, 2, 26, lower.tail = F ) . Why !!!
– ABC
Commented Apr 11, 2015 at 1:36
• It is still working: pf ( 330.285, 6, 9, lower.tail = F ) [1] 4.984053e-10 Commented Apr 11, 2015 at 1:37
• Try reinstalling your R and stats package Commented Apr 11, 2015 at 1:39
• ABC -- I bet you have defined F as a variable which it will then use. What happens when you do str(F)? ... to be safe, always type FALSE in full. Commented Apr 11, 2015 at 1:46

I'm guessing that the problem is that you have F defined as a variable. Try

pf(330.285, 6, 9, lower.tail = FALSE)

Let this be a lesson to you: use TRUE and FALSE, not T and F!

• Yes , you are absolutely right. I've defined F=330.285 and also wrote lower.tail=F .
– ABC
Commented Apr 11, 2015 at 2:13