Results 1 to 3 of 3

Math Help - Manipulating the sample variance formula

  1. #1
    Newbie
    Joined
    May 2011
    Posts
    9

    Manipulating the sample variance formula

    Hello.

    I am trying to prove the identity in red. (My failed attempt is in black)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Dec 2009
    Posts
    3,120
    Thanks
    1

    Re: Manipulating the sample variance formula

    Quote Originally Posted by incblue View Post
    Hello.

    I am trying to prove the identity in red. (My failed attempt is in black)
    If you multiply out the numerator of the red LHS,
    then use the fact that

    \sum{x_i}=n(mean)

    the result follows.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    May 2011
    Posts
    9

    Re: Manipulating the sample variance formula

    Quote Originally Posted by Archie Meade View Post
    If you multiply out the numerator of the red LHS,
    then use the fact that

    \sum{x_i}=n(mean)

    the result follows.
    Thanks, it was easy after applying that.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Prove the sample variance formula.
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: September 9th 2010, 03:06 AM
  2. Variance of the sample mean formula.
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: September 7th 2010, 09:57 PM
  3. Sample distribution of sample variance
    Posted in the Statistics Forum
    Replies: 10
    Last Post: November 16th 2009, 12:12 PM
  4. variance of sample mean and sample standard deviation
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: July 24th 2009, 05:20 AM
  5. manipulating a physics formula
    Posted in the Math Topics Forum
    Replies: 3
    Last Post: March 30th 2008, 06:01 AM

Search Tags


/mathhelpforum @mathhelpforum