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iPadThai
New Orleans Saints Fan
Member since Oct 2011
713 posts

Weighted average problem with negative numbers


Let's say I have 4 values A, B, C and D. Let's say they each contribute 30%, 30%, 20% and 20% towards some final value.

So my weighted average formula is:

X = [0.3(A) + 0.3(B) + 0.2(C) + 0.2(D)] / [0.3+0.3+0.2+0.2]

But what if the situation is such that values C and D contribute negatively to the over all value X?

As a sports analogy using a hypothetical situation, let's say I am calculating a Quartback's rating using my own method as follows:

A = Yards/Attempt (I want this to be high, so this is a positive value) - 30% weight
B = Touchdown percentage (I want this to be high, so this is a positive value) - 30% weight
C = Number of incomplete passes (I want this number to be low/minumum and it contributes negatively to the overall rating) - 20% weight
D = Interception percentage (Needs to be minimized and contributes negatively to the overall rating) - 20% weight

So for my overall weighted average QB rating can I use this formula?

X = [0.3(A) + 0.3(B) - 0.2(C) - 0.2(D)] / [0.3+0.3+0.2+0.2]

If this is wrong, how to I account of positive and negative numbers in the same weighted average formula?



This post was edited on 11/29 at 11:51 pm



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hg
Toledo Fan
Member since Jun 2009
65717 posts
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re: Weighted average problem with negative numbers








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JLSIX
New Orleans Saints Fan
Member since Apr 2010
21509 posts

re: Weighted average problem with negative numbers


288





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TigerHam85
Hawaii Fan
59-024 Kamehameha Highway, Haleiwa
Member since Nov 2009
24859 posts

re: Weighted average problem with negative numbers


288


eta: damnit!



This post was edited on 11/29 at 11:49 pm


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Joe
LSU Fan
North Jersey
Member since Jan 2005
5924 posts

re: Weighted average problem with negative numbers


The plane takes off.


This post was edited on 11/29 at 11:49 pm


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Hazelnut
LA-Lafayette Fan
The Flattz
Member since May 2011
11222 posts

re: Weighted average problem with negative numbers


TL,DR

Too Late, didn't read






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KosmoCramer
USA Fan
Member since Dec 2007
42366 posts

re: Weighted average problem with negative numbers


288





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Harry Caray
USA Fan
Astros 2016 AL West Champs
Member since Aug 2009
13330 posts

re: Weighted average problem with negative numbers


quote:

X = [0.3(A) + 0.3(B) - 0.2(C) - 0.2(D)] / [0.3+0.3+0.2+0.2]


well, this leaves your maximum possible rating at 60%

ETA: 288



This post was edited on 11/29 at 11:51 pm


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iPadThai
New Orleans Saints Fan
Member since Oct 2011
713 posts

re: Weighted average problem with negative numbers


quote:

well, this leaves your maximum possible rating at 60%

That is what I am afraid I am doing wrong.

How can I account for the positive and negative weights at the same time while making sure they add up to 100%?






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lsu480
Arizona State Fan
Downtown Scottsdale
Member since Oct 2007
61756 posts
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re: Weighted average problem with negative numbers


It's 2







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Vicks Kennel Club
USA Fan
2013 TDFL Champion
Member since Dec 2010
16812 posts

re: Weighted average problem with negative numbers


Why do you keep writing the denominator? It is just one in your formula.





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Harry Caray
USA Fan
Astros 2016 AL West Champs
Member since Aug 2009
13330 posts

re: Weighted average problem with negative numbers


quote:

How can I account for the positive and negative weights at the same time while making sure they add up to 100%?


idk, take a class.

ETA: study the passer rating stat...even though it maxes out at 158.3 instead of 100, it'll give you an idea.



This post was edited on 11/29 at 11:58 pm


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au21tigers
North Carolina Fan
Huntsville
Member since Nov 2009
7900 posts

re: Weighted average problem with negative numbers


LINK





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ConwayTwizzle
Alabama Fan
Little Havana
Member since Nov 2012
1887 posts

re: Weighted average problem with negative numbers


tl;dr but it's either 2 or 288






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Vicks Kennel Club
USA Fan
2013 TDFL Champion
Member since Dec 2010
16812 posts

re: Weighted average problem with negative numbers


quote:

It's 2



I probably made some of my best arguments ever in that thread.






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lsu480
Arizona State Fan
Downtown Scottsdale
Member since Oct 2007
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re: Weighted average problem with negative numbers








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Gator5220
Florida Fan
Member since Aug 2010
771 posts

re: Weighted average problem with negative numbers


I'll take a whopper no onion please.





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Macintosh504
New Orleans Pelicans Fan
Member since Sep 2011
20947 posts

re: Weighted average problem with negative numbers


288

yes, I'm a genius






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iPadThai
New Orleans Saints Fan
Member since Oct 2011
713 posts

re: Weighted average problem with negative numbers


Can somebody from the day crew weigh-in with their thoughts please? Thanks.





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