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!

Homework Help: T distribution?

  1. Oct 20, 2008 #1
    t distribution??

    1. The problem statement, all variables and given/known data
    If U and V are independent, U being distributed N(3,16) and V being distributed as chi-square on 9 degrees of freedom, find

    P(U-3 < 4.33 sqrtV).

    2. Relevant equations

    3. The attempt at a solution
    Well I don't even know where to start!! Does U-3 suggest the mean is 0? Is the whole distribution of U shifted left by 3? Does that give a t distribution?
    I am not asking for the answer but some direction would be appreciated, I just can't seem to understand this at all.
  2. jcsd
  3. Oct 20, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Re: t distribution??

    U-3 is distributed N(0,16).
  4. Oct 21, 2008 #3
    Re: t distribution??

    Ok, I understand this and also can reason that the probability would be very high, just by thinking of the graphs of the distributions, however I am still at a loss as to how to compute the probability. I use R to do the calculations, is it some kind of t test or do I put in the distributions and their parameters and just use R to calculate the probability, if so... is the R code just the same as in the question, that is, P(U-3 < 4.33 sqrtV)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook