Weighted average problem with negative numbers | TigerDroppings.com

Posted byMessage
iPadThai
New Orleans Saints Fan
Member since Oct 2011
743 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



Back to top
Share:
hg
LSU Fan
Member since Jun 2009
71853 posts
 Online 

re: Weighted average problem with negative numbers








Back to top
  Replies (0)
John McClane
New Orleans Saints Fan
Member since Apr 2010
24247 posts
 Online 

re: Weighted average problem with negative numbers


288





Back to top
  Replies (0)
TigerHam85
Hawaii Fan
59-024 Kamehameha Highway, Haleiwa
Member since Nov 2009
27499 posts

re: Weighted average problem with negative numbers


288


eta: damnit!



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


Back to top
  Replies (0)
Joe
LSU Fan
North Jersey
Member since Jan 2005
5980 posts

re: Weighted average problem with negative numbers


The plane takes off.


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


Back to top
  Replies (0)
Hazelnut
LA-Lafayette Fan
The Flattz
Member since May 2011
11553 posts

re: Weighted average problem with negative numbers


TL,DR

Too Late, didn't read






Back to top
  Replies (0)
KosmoCramer
Cornell Fan
Member since Dec 2007
44279 posts

re: Weighted average problem with negative numbers


288





Back to top
  Replies (0)
Harry Caray
USA Fan
Astros 2016 AL West Champs
Member since Aug 2009
13582 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


Back to top
iPadThai
New Orleans Saints Fan
Member since Oct 2011
743 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%?






Back to top
lsu480
LSU Fan
Downtown Scottsdale
Member since Oct 2007
69571 posts
 Online 

re: Weighted average problem with negative numbers


It's 2







Back to top
Vicks Kennel Club
USA Fan
LegenD Forever
Member since Dec 2010
19582 posts
 Online 

re: Weighted average problem with negative numbers


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





Back to top
  Replies (0)
Harry Caray
USA Fan
Astros 2016 AL West Champs
Member since Aug 2009
13582 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


Back to top
  Replies (0)
au21tigers
Auburn Fan
ask your wife
Member since Nov 2009
12118 posts
 Online 

re: Weighted average problem with negative numbers


LINK





Back to top
  Replies (0)
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






Back to top
  Replies (0)
Vicks Kennel Club
USA Fan
LegenD Forever
Member since Dec 2010
19582 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.






Back to top
lsu480
LSU Fan
Downtown Scottsdale
Member since Oct 2007
69571 posts
 Online 

re: Weighted average problem with negative numbers








Back to top
  Replies (0)
Gator5220
Florida Fan
Member since Aug 2010
855 posts
 Online 

re: Weighted average problem with negative numbers


I'll take a whopper no onion please.





Back to top
  Replies (0)
Macintosh504
LSU Fan
Member since Sep 2011
23481 posts
 Online 

re: Weighted average problem with negative numbers


288

yes, I'm a genius






Back to top
iPadThai
New Orleans Saints Fan
Member since Oct 2011
743 posts

re: Weighted average problem with negative numbers


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





Back to top
  Replies (0)


Back to top