Backward Way of Working...

**Triple L** · 05-26-2010, 05:21 PM

Hi,

This one is slightly different to your normal questions of "how do I do this"...This is one is a "what has been done to produce the following..."

Using the following percentages:

Poland Availability: 42.579%
Hungary Availability: 39.370%
Czech Availability: 37.515%
Slovakia Availability: 37.401%

This percentage has been created:

Total Availability: 38.684%

...And I cannot for the life of me work out how...
I think it's through the use of a weighted average, but not exactly sure how you would go about creating that calculation in Excel?

Anyone help??

**daddylonglegs** · 05-26-2010, 05:26 PM

Well it isn't a straight average as you probably know, so it could be a weighted average....but you'd need to know the weights, if %s are in A2:A5 and the weights in B2:B5 you could get the result with

=SUMPRODUCT(A2:A5,B2:B5)/SUM(B2:B5)

**squiggler47** · 05-26-2010, 05:28 PM

it looks to me more like the %age is based on the original figures used to produce the %ages

averaging %ages wouldnt make sense unless you know one of the figures its based on!

**Triple L** · 05-26-2010, 05:38 PM

Okay...Thought this might be the case, that there wasn't enough info to work with...
So here's a snap shot of what I get every Monday morning...

[Removed]

What I'm interested in specifically is the 3rd in from the left and the last columns as this is where the suspected weighted averages are that I could do with producing - any help??

Thanks,

**daddylonglegs** · 05-26-2010, 05:59 PM

Well, looking at the first line the 0.430970897 figure (43.097%) seems to be a % increase from 38028 to 54417, so if those figures are in B2 and C2 you'd get the % with this formula

=B2/C2-1

Not sure about the last column, doesn't seem so obvious to me.....