# Weighted Average Predictions

• Jun 29th 2012, 12:34 PM
DaFonz01
Weighted Average Predictions
I have a math problem that I am not sure how to solve.

My question is, based on my current variances and weighted averages, what can you predict that my variance will be based on the new weighted average from June - December

Variance from January to May
Construction: 83% Variance - Weighted Average - 36%
Materials: 99% Variance - Weighted Average - 22%
Overheard: 94% Variance - Weighted Average - 42%
TOTAL: 92% - Variance

Based on Projections of spend from June - December here is the change of the Weighted Average
June - December:
Construction - Weighted Average - 36%
Materials: - Weighted Average - 38%
Overheard: - Weighted Average - 26%

Summary
Construction weighted average stays the same
Materials - Increased 17%
Overheard - Decreased 17%

Thanks a million if anyone can help me with this. I not even sure if you can draw a conclusion.
• Jul 1st 2012, 06:18 AM
mfb
Re: Weighted Average Predictions
At least to me, it is unclear what your numbers mean and what you want to evaluate.

For example:
"Construction: 83% Variance"
Is that some variance in some costs, for example? % relative to what?

"Weighted Average - 22%"
That is the weight of the materials value. Where does it come from? It changed later?

What do you want to calculate? The weighted average with the new numbers? This would just be 83%*0.36+99%*0.38+94%*0.26=91.94%
However, I am not sure whether that value has any meaning.
• Jul 2nd 2012, 09:39 PM