keeping a running sum of a formula with conditions - excel

Question

I am having an issue with an excel problem and cannot use vba or add any extra columns. The problem goes along with the format of this image. I could not find anything on google that helped me with this problem and im sorry if it has been asked before.
Example Image
On a separate page in a cell i need to write a function that will check if Info 2 = "z" and Info4 = "x" and if that is true then i need to do the following equation with the numbers in Info1 and Info3: Info1*(1 - Info3)
I will also have to keep a sum of these numbers.
For this example I would want the cell with the formula to equal -34 by doing the following:
3*(1-4)+5*(1-6) = -34
I would want the cell to just display the finished sum
Any help would be greatly appreciated,
Thank you!

Answer 1

You are looking for the mighty powers of SUMPRODUCT
=SUMPRODUCT((B:B="z")*(D:D="x")*(A:A)*(1-C:C))
The first two multipliers will make sure we only evaluate those rows having z for B and x for D. While the latter two are your desired function. Excel will evaluate this for each row and sum up the results.

Answer 2

I am using psuedo values below but this should work:
= [value of cell above] + if(and([info2] = "z" , [info4] = "x"), [info1]*(1-[info3]),0)
so basically starting in the middle, you have a two truth tests,
[info2] = "z", [info4]= "x"
using AND() requires they both pass
and([info2] = "z", [info4]= "x")
if they do pass you want to do your formula:
if(and([info2] = "z" , [info4] = "x"), [info1]*(1-[info3]),FALSE)
but since we want to sum all values for each iterative row we make not passing this test 0:
if(and([info2] = "z" , [info4] = "x"), [info1]*(1-[info3]),0)
Ok so this works for one row, but doesn't sum the numbers from the tests on the previous row:
= [value of cell above or 0 for first row] + if(and([info2] = "z" , [info4] = "x"), [info1]*(1-[info3]),0)
an example written with real excel ranges that you may have to tweak depending on where your values are stored:
Sample picture