Filling a cell with using conditional formatting in two other cells

Hi,

I've been having some hard time figuring out how to solve this.

I have three columns with actual data (numbers) and would like to illustrate conclusions based on the first and third cell into a fourth cell in colors.

Let's say that my borderline is 4 and all numbers higher that that should first turn the respective cell (1st and 3rd) into red and at the same time turn the fourth summary cell red as well. 

This works well for the first row , but I need 70 rows with the same logic.  When I copy this described logic for remaining 69 rows, it blows out: the value inserted into first row turns other rows red as well. Some how I would need to define that this color logic is depended into the precise row.

Any ideas how to do it ?

cheers, jouko