Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Another probability problem

  1. Oct 22, 2008 #1
    1. http://d.imagehost.org/t/0866/problem1.jpg [Broken]

    2. Relevant equations

    3. For the Poisson random variables I get ((lamda)^x)/((e^2lambda)*x!) when y =1. Is this a Poisson Random variable? Also, when y = 0, I get ((lamda)^x)/((e^lambda)*x!) - ((lamda)^x)/((e^2lambda)*x!) I cannot get the binomial. I don't know how to show that this is Binomial as x is in the range from 1...infinity.

    For part 1 I used the fact that P(X=x and Y=y) = P(X|Y)P(Y)
    and P(Y=y) = sum(1 to x)P(X=x and Y=y) = 1, so P(X=x|Y=y)(P(y) = P(X=x and Y=y)
    Reply With Quote
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Oct 22, 2008 #2
    http://d.imagehost.org/view/0752/problem1.jpg [Broken]
    Last edited by a moderator: May 3, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook