Results 1 to 1 of 1

Math Help - Proving the SST = SSE + SSR

  1. #1
    Newbie
    Joined
    Nov 2010
    Posts
    5

    Proving the SST = SSE + SSR

    I need help with this last part of this proof. This is my first time using the forums so I'm not sure how to write all the symbols but I will make it as clear as possible:

    SST = SUM [(yi-yavg)^2]
    SST = SUM [(yi-yavg + yi hat - yi hat)^2]

    This ends up afters foiling:

    SST = SSE + SSR + 2SUM[(yi hat - yavg)(yi - y hat)]

    I can't figure out how to show that the last term is zero. My professor says to use

    y hat = B0+B1*Xi

    B0 = yavg -Bi*xavg

    and

    B1 = SUM [ ((xi - xavg)*(yi-yavg))/((xi-xavg)^2)]

    but I can't get it to work out. I get

    Which leads me to

    SUM[ xi * ( yi - yavg + SUM[ ((xi - xavg)*(yi-yavg))/((xi-xavg)^2)] * (xavg - xi)]

    Maybe I am forgeting a trick for dealing with nested summation..

    Help! and Thanks in advance!
    Last edited by Seda1; November 9th 2010 at 10:30 AM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Proving y^2=-4x
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: May 27th 2010, 08:48 AM
  2. Proving CRT
    Posted in the Advanced Algebra Forum
    Replies: 11
    Last Post: April 13th 2010, 11:14 PM
  3. proving
    Posted in the Discrete Math Forum
    Replies: 4
    Last Post: April 11th 2010, 01:49 AM
  4. Please me proving this.
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: March 28th 2010, 12:29 AM
  5. Proving an identity that's proving to be complex
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: July 21st 2009, 02:30 PM

Search Tags


/mathhelpforum @mathhelpforum