
Advanced Statistics Advanced Probability and Statistics Math Forum 
 LinkBack  Thread Tools  Display Modes 
September 13th, 2007, 05:17 PM  #1 
Newbie Joined: Sep 2007 Posts: 1 Thanks: 0  Forecasts for groups of items tend to be more accurate...
Hey! Does anyone have an idea how to mathematically prove that "Forecasts for groups of items tend to be more accurate than forecasts for individual items because forecasting errors among items in a group usually have a cancelling effect." ? Appreciate any response, Alex 
September 14th, 2007, 06:42 AM  #2 
Global Moderator Joined: Nov 2006 From: UTC 5 Posts: 16,046 Thanks: 938 Math Focus: Number theory, computational mathematics, combinatorics, FOM, symbolic logic, TCS, algorithms 
Most of the work would be in stating the problem mathematically. For example, if the statement was: "Suppose x_1, x_2, ..., x_n are real numbers. Then (x_1 + x_2 + ... + x_n)/n >= (x_1 + x_2 + ... + x_n)/n." This shows that in the worst case the average total error is the same as the average individual error. 

Tags 
accurate, forecasts, groups, items, tend 
Search tags for this page 
Click on a term to search for related topics.

Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
NPComplete  Superfluidity and if accurate Navier Stokes  BenFRayfield  Applied Math  0  August 23rd, 2013 09:57 AM 
Is this accurate? It looks funky...  CherryPi  Number Theory  7  January 6th, 2012 06:46 PM 
Sum, which is more accurate?  args0  Applied Math  2  February 9th, 2011 03:47 PM 
How Accurate is Trigonomety for angular measurements?  manich44  Algebra  1  June 10th, 2009 08:32 AM 
Partial pivoting more accurate?  cosmin  Algebra  2  August 9th, 2008 02:59 AM 