Results 1 to 2 of 2

Math Help - variance

  1. #1
    Newbie
    Joined
    Apr 2008
    Posts
    19

    variance

    The random variable X takes on the values 5, 20, 30, and 200
    with probabilites 0.60, 0.30, 0.08, and 0.02 respectively.
    find the VARIANCE of the random
    variable X..
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by ballin_sensation View Post
    The random variable X takes on the values 5, 20, 30, and 200
    with probabilites 0.60, 0.30, 0.08, and 0.02 respectively.
    find the VARIANCE of the random
    variable X..
    V=E((X-\overline{X})^2)=\sum_{i=1}^4 (x_i-\overline{X})^2\;p(x_i)

    \overline{X}=E(X)=\sum_{i=1}^4 x_i\;p(x_i)

    So now you can either do this or you have a problem in doing the above, if so tell us and we will try to sort out you problem.

    CB
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Help with variance
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: September 3rd 2011, 02:53 AM
  2. variance of the sample variance
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: February 8th 2011, 09:35 PM
  3. How to get new variance given old variance and average
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 23rd 2010, 06:39 AM
  4. Variance Help
    Posted in the Statistics Forum
    Replies: 2
    Last Post: August 23rd 2009, 02:22 PM
  5. Variance of the population variance.
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: November 10th 2008, 10:07 AM

Search Tags


/mathhelpforum @mathhelpforum