if you have the time- sum product explaination

[Dryver14]

I hope someone can breakdown the sumproduct formula for me it just isnt sinking in.

be it with -- or *

I sort of understand or think I do then see someones answer which I run off and copy to try and get it but ......nope.

 

[VoG]

Take a look here http://www.xldynamic.com/source/xld.SUMPRODUCT.html

 

[Dryver14]

Thanks VoG that looks brilliant Im off to have a good read of it, it seems to break it right down