skipping columns part 2

[Wazooli]

Earlier, I asked how I could skip columns, and was answered in the
following manner:

On cell A700 type
=AVERAGE(OFFSET($E$3,0,COLUMN()*7-7,648))
aand copy it across B700 and so on .

Now I am asking if I can use the above with an array formula. My data
is 'raw data'!e3:e650 and 'raw data'!f3:f650. I would like to simply
divide the two columns and get an average, and can do so using an array
formula:
{=average((e3:e650)/(f3:f650))

My question is how can I do this calculation on a different sheet, using
OFFSET as above. I have tried,

{=AVERAGE(OFFSET('raw
data'!$E3,0,COLUMN()*7-14,648))/AVERAGE(OFFSET('raw
data'!$F3,0,COLUMN()*7-14,648))},

but the value given is incorrect.

Any help is appreciated.

Wazooli

P.S. - I had to modify the above OFFSET formula to read
"...COLUMN()*7-14...", instead of "...COLUMN()&7-7..."