Results 1 to 2 of 2

Math Help - Density Function

  1. #1
    Member
    Joined
    Apr 2008
    Posts
    132

    Density Function

    If X and Y are continuous random variables with joint probability density function



    a) Calculate the marginal density function (fx) of X.

    b)Determine whther or not X and Y are independent.

    Would i be right in saying that part a) is 12x.
    And that they are noy independent because their both marginal density functions multiply to 144xy.
    Any guidance wold be great
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by matty888 View Post
    If X and Y are continuous random variables with joint probability density function



    a) Calculate the marginal density function (fx) of X.

    b)Determine whther or not X and Y are independent.

    Would i be right in saying that part a) is 12x. Mr F says: No.
    And that they are noy independent because their both marginal density functions multiply to 144xy.
    Any guidance wold be great
    f_X(x) = \int_{y = 0}^{y = -x+1} 24xy \, dy = 12x(1-x)^2.

    It is evident from the region over which the joint pdf is non-zero that X and Y are NOT independent.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Finding a Cumulative Distribution Function and Density Function
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: November 17th 2011, 10:41 AM
  2. Replies: 4
    Last Post: October 27th 2010, 06:41 AM
  3. Replies: 1
    Last Post: April 10th 2009, 11:59 AM
  4. p.g.f / density function
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 17th 2009, 03:20 AM
  5. Density function
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: April 5th 2008, 01:26 PM

Search Tags


/mathhelpforum @mathhelpforum