Results 1 to 4 of 4

Thread: [SOLVED] Probability (probability mass function,pmf)

  1. December 14th 2009, 11:21 PM #1
    nameck
    nameck is offline
    Member
    Joined
    Nov 2009
    Posts
    151

    [SOLVED] Probability (probability mass function,pmf)

    If X has the probability mass function f(x) = k / x! (x=0,1,2,...),
    what is the value of k?
    Follow Math Help Forum on Facebook and Google+
  2. December 15th 2009, 03:11 AM #2
    HallsofIvy
    HallsofIvy is online now
    MHF Contributor
    Joined
    Apr 2005
    Posts
    13,721
    Thanks
    545
    Quote Originally Posted by nameck View Post
    If X has the probability mass function f(x) = k / x! (x=0,1,2,...),
    what is the value of k?
    You must have \sum_{x=0}^\infty \frac{k}{x!}= k\sum_{x=0}^\infty \frac{1}{x!}= 1.
    Follow Math Help Forum on Facebook and Google+
  3. December 15th 2009, 03:18 AM #3
    nameck
    nameck is offline
    Member
    Joined
    Nov 2009
    Posts
    151
    how to cancel the factorial(!) sign?
    Follow Math Help Forum on Facebook and Google+
  4. December 15th 2009, 06:30 AM #4
    Plato
    Plato is online now
    MHF Contributor
    Joined
    Aug 2006
    Posts
    16,996
    Thanks
    776
    Awards
    1
    MHF Donor
    Quote Originally Posted by nameck View Post
    how to cancel the factorial(!) sign?
    At this level you are expected to know that \sum\limits_{x = 0}^\infty {\frac{1}{{x!}}} = e.
    Follow Math Help Forum on Facebook and Google+
« Area between two curves with abs value. | Linearization problem »

Similar Math Help Forum Discussions

  1. Probability mass function
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: October 21st 2010, 03:07 AM
  2. Probability mass function
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 31st 2010, 07:37 PM
  3. [SOLVED] Probability mass function - Can anyone help me?
    Posted in the Statistics Forum
    Replies: 1
    Last Post: November 12th 2009, 08:33 AM
  4. Probability mass function
    Posted in the Statistics Forum
    Replies: 1
    Last Post: March 14th 2009, 12:31 PM
  5. Probability mass function
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: March 31st 2008, 05:26 AM

Search Tags


/mathhelpforum @mathhelpforum