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New Orleans Saints Fan
Member since Oct 2011
908 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

hg
Miami (FL) Fan
Member since Jun 2009
97112 posts

re: Weighted average problem with negative numbers

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John McClane
New Orleans Saints Fan
Member since Apr 2010
31555 posts

re: Weighted average problem with negative numbers
288

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TigerHam85
Hawaii Fan
59-024 Kamehameha Highway
Member since Nov 2009
31493 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
6136 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
Choclate City
Member since May 2011
14337 posts

re: Weighted average problem with negative numbers
TL,DR

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00
KosmoCramer
Ohio State Fan
Member since Dec 2007
57596 posts

re: Weighted average problem with negative numbers
288

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Harry Caray
Houston Astros Fan
Denial
Member since Aug 2009
15371 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

New Orleans Saints Fan
Member since Oct 2011
908 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%?

lsu480
LSU Fan
Downtown Scottsdale
Member since Oct 2007
88076 posts

re: Weighted average problem with negative numbers
It's 2

Vicks Kennel Club
Chicago Cubs Fan
Kris Bryant Fan
Member since Dec 2010
28154 posts
Online

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
Houston Astros Fan
Denial
Member since Aug 2009
15371 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
Auburn Fan
Thursday
Member since Nov 2009
12548 posts

re: Weighted average problem with negative numbers

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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
Chicago Cubs Fan
Kris Bryant Fan
Member since Dec 2010
28154 posts
Online

re: Weighted average problem with negative numbers
quote:

It's 2

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

lsu480
LSU Fan
Downtown Scottsdale
Member since Oct 2007
88076 posts

re: Weighted average problem with negative numbers

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Gator5220
Florida Fan
Member since Aug 2010
1403 posts

re: Weighted average problem with negative numbers
I'll take a whopper no onion please.

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Macintosh504
Hawaii Fan
Loving Spirits University
Member since Sep 2011
33483 posts
Online

re: Weighted average problem with negative numbers
288

yes, I'm a genius

New Orleans Saints Fan
Member since Oct 2011
908 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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