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: Binomial distribution smallest value

  1. Jan 5, 2005 #1
    could someone please shed some light upon the following dilemma:

    Given that D~B(12,0.7), calculate the smallest value of d such that
    P(D>d) <0.90.

    much obliged
  2. jcsd
  3. Jan 5, 2005 #2
    I am going to replace the D with an X and the d with an x and the B with a Bin.

    From this you know that n=12, p=0.7, q=0.3 and x=d.
    n is the number of trials, p is the probability of the event n happening and q is 1 - p.

    So X~Bin(12,0.7) = [tex]^nC_r p^r q^n^-^r = ^{12}C_0[/tex] [tex]0.7^0[/tex] [tex]0.3^{12} = 1\times1\times0.0053 = 0.0053[/tex]

    All you then need to do this for the next few until you get an answer which answers your question.

    The Bob (2004 ©)

    EDIT: I think this post needs a little more information but I have not the time now. Sorry.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook