Here is what I am using:

Range("E2").Select
ActiveCell.FormulaR1C1 = "=RC4/R51C4"
Range("E2").Select
Selection.AutoFill Destination:=Range("E2:E49")

That selects E2, applies the formula and autofills down to the last cell
with values in it which happens to be row 49. NOW, how do I code it to do
that regardless of how many rows are in the imported data. Because some data
will be 60 rows long, others will be 50, etc. That formula selects
specifically that amount and I want it to just select the whole column
regardless of amount of rows. Make sense?

So I'm assuming some kind of change to:

Selection.AutoFill Destination:=Range("E2:E49")

or am I way off???

THANKS!!!