September 2013

Discussion in 'CT6' started by jm_kinuthia, Oct 7, 2013.

  1. jm_kinuthia

    jm_kinuthia Member

    I hope we are now allowed to post.

    How did you find the exam ?

    Imo it was harder than the April paper which had a very high pass rate and also quite long.
     
    jm_kinuthia, Oct 7, 2013
    #1
  2. gnarly

    gnarly Member

    I thought it was an odd paper and also too long - didnt answer 18 marks!
     
    gnarly, Oct 7, 2013
    #2
  3. Mathildachen86

    Mathildachen86 Member

    odd

    it is odd and long. I do agree.

    So much Bayesian!!
     
    Mathildachen86, Oct 8, 2013
    #3
  4. Niranjan

    Niranjan Member

    so much emphasis on bayesian stats

    I find the questions are not that tough but they are very lengthy and I don't think that anybody can attempt all the questions in 3 hours. it is just impossible to attempt 100 marks paper.:(
     
    Niranjan, Oct 8, 2013
    #4
  5. John Lee

    John Lee ActEd Tutor Staff Member

    YouTube exam review

    If you're interested, I have uploaded an exam review of this paper on YouTube.

    You can find it here.
     
    John Lee, Oct 9, 2013
    #5
  6. jm_kinuthia

    jm_kinuthia Member

    Thanks so much John.
     
    jm_kinuthia, Oct 9, 2013
    #6
  7. Tele76

    Tele76 Member

    Just going through this paper now for revision.

    Can anyone help explain this step from question 9 part ii ?


    We have the defining equation: Xt = a1Xt-1 + a2Xt-2 + B1et-1 + et

    then Cov(Xt,et-1) = aCov(Xt-1,et-1) + B1(sigma^2) + sigma^2


    After this step the remainder of the question is pretty straightforward.


    I'm sure this is just basic covariance algebra, but struggling to work it out for some reason, .....
     
    Tele76, Apr 1, 2014
    #7
  8. Hemant Rupani

    Hemant Rupani Senior Member

    How you've got Last term sigma^2 ?
    Its not correct.
     
    Hemant Rupani, Sep 17, 2014
    #8

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