Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

Moment generating function for discrete probability mass function?

Given the discrete r.v. X

with the Probability Mass Function

P(X=x) = 2 (1/3)^x

Find its Moment Generating Function.

Update:

x = 1,2,3,...

Update 2:

I think your answer is wrong since from what I know MGF is E(e^tx) .

2 Answers

Relevance
  • 4 years ago

    Mgf Probability

  • cidyah
    Lv 7
    1 decade ago

    MGF = E(t^x)

    = 2 Σ t^x(1/3)^x

    =2 Σ (t/3)^x , x=1,2,.....

    Σ (t/3)^x is a geometric series with common ratio t/3 and has the sum:

    (t/3) / [1-t/3]

    = t /(3-t)

Still have questions? Get your answers by asking now.