april 2017 question 5.2

Discussion in 'CT6' started by dushyant kochar, Jun 11, 2017.

  1. 5 (i) -Show that the following discrete distribution { Bin(n,p) } belongs to the exponential family of distributions.

    (ii) Derive expressions for the mean and variance of the distribution, E(y) and Var(y), using your answer to part (i).
    [4 marks each]
    in part 2 of the question what examiners are exactly looking for? do they want us to prove that
    E(Y) =b'(Q) and var(Y) = a(o)b''(Q)
    or they want us to use the result E(Y) =b'(Q) and var(Y) = a(o)b''(Q) and derive the mean and variance of y in terms of n and p ? plz help,
     

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    Last edited by a moderator: Jun 12, 2017
  2. John Lee

    John Lee ActEd Tutor Staff Member

    It was unfortunate wording - as "derive" implies that we should derive the formulae (like we did in 2016) but the marks suggests otherwise. In this case it just meant quote and use the formulae.
     
    dushyant kochar likes this.
  3. Thank u sir :)
     
  4. Sir the results came out and i cleared the paper:D. Thank u very much John sir for all your help , it mattered a lot:)
     

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