Excel - Replicating a SUMPRODUCT formula with already summed up values

Question

I have a sheet that uses the below formula to arrive at a figure:

=SUMPRODUCT(E12:K12,E23:K23)/M10

To my understanding, it's getting the sum of E12:K12(593+622+636+620+595+583+589) and multiplying that together with the sum of E23:K23(5740+5160+5432+4640+4716+7372+6696); then dividing the result by M10(39,756).

I have 2 new cells that contain the results of the two summed ranges but when I try to replicate the formula with a regular sum, the result is different:

=SUM(IntradayPlan2!D346*IntradayPlan2!D347)/P12

The result should be 604 but it's coming out at 4383. P12 contains the same number as M10 and the 2 cells in the SUM are summing the same values as the original SUMPRODUCT formula is.

For clarity, I'm currently replicating the main sheet a second time to generate this result. It's slowing down the workbook and most of the other detail on the replicated sheet isn't needed, so I'm trying to get rid of it.

I'm sure I'm missing something when it comes to SUMPRODUCT but after an hour of Googling around I can't work it out. Is there a way of replicating the same maths procedure with my new totals instead?

Answer 1

After the great explanation by Gowtham I don't think it's possible to recreate the result of a SUMPRODUCT by using total values of the 2 used arrays.

Those cells actually get their values from another sheet, which I need to keep anyway. So I've created a couple of new rows which puts those figures in a line (their otherwise spread out across the sheet) and have referenced those new groups instead.

=SUMPRODUCT(IntradayPlan2:D355,J355:IntradayPlan2!D356:J356)/O12

And I'm getting the expected result:)