Results 1 to 3 of 3

Math Help - Discrete Random Variables

  1. #1
    Senior Member I-Think's Avatar
    Joined
    Apr 2009
    Posts
    288

    Discrete Random Variables

    Hi. Glad to see that we're being reminded of the rules. Here's a question on random variables.

    The discrete random variable X has a probability density function

     <br />
P(X=x)= \frac{x}{10}   where x= 1, 2, 3, 4<br />

    P(X=x) is 0 otherwise


    If Y denotes the sum of two independent observations of X
    Determine the value of P(Y=4)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,957
    Thanks
    1781
    Awards
    1
    Quote Originally Posted by I-Think View Post
    The discrete random variable X has a probability density function  <br />
P(X=x)= \frac{x}{10}   where x= 1, 2, 3, 4
    P(X=x) is 0 otherwise
    If Y denotes the sum of two independent observations of X
    Determine the value of P(Y=4)
    Note that elementary event Y=4 is simply {(1,3),(3,1),(2,2)}.
    Calculate the probabilities of each and add.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member I-Think's Avatar
    Joined
    Apr 2009
    Posts
    288
    Silly statistician, integration is for continuous random variables.

    Sorry about this question, for some strange reason I thought this was a continuous random variable, and continued in this erroneous belief even after your help.

    Oh well, everybody makes mistakes in life, and maths.

    Thanks for your help. (Please don't remind me of the thread's title)
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Discrete random variables
    Posted in the Advanced Statistics Forum
    Replies: 4
    Last Post: October 11th 2010, 11:15 AM
  2. Discrete random variables (2)
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: October 11th 2010, 10:31 AM
  3. Replies: 3
    Last Post: January 13th 2010, 11:44 AM
  4. discrete random variables
    Posted in the Statistics Forum
    Replies: 2
    Last Post: October 9th 2008, 05:47 AM
  5. Discrete Random Variables
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 27th 2008, 06:55 AM

Search Tags


/mathhelpforum @mathhelpforum