1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Probability Question - Exponential Distribution

  1. Mar 15, 2013 #1
    1. The problem statement, all variables and given/known data

    Suppose that X has an exponential distribution with mean μ. Find the probability that x lies within one standard deviation of its mean, that is find P(μ-σ≤X≤μ+σ)

    2. Relevant equations



    3. The attempt at a solution

    If I'm not mistaken the standard deviation is equal to the mean of an exponential distribution so isn't the answer just zero or am I missing something important here?
     
  2. jcsd
  3. Mar 15, 2013 #2

    Ray Vickson

    User Avatar
    Science Advisor
    Homework Helper

    Yes. You are missing the facts that μ-σ = 0 and μ+σ = 2μ, so you want P(0 ≤ X ≤ 2μ). Why would you suppose that is 0?
     
  4. Mar 15, 2013 #3
    oh thanks i missed that
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Probability Question - Exponential Distribution
Loading...