Results 1 to 4 of 4

Math Help - Poisson distribution

  1. #1
    Newbie
    Joined
    Oct 2010
    Posts
    4

    Poisson distribution

    A manufacturer of rockets estimates that on average 1 in 75 of the rockets fail to burn properly.Using this estimate, and a Poisson distribution, find an approximate value for the probability that out of 225 randomly chosen rockets at most 221 burn properly.

    How do i solve this question using poisson distribution? I solve this question using binomial dist, using X~B(225,74/75) P(Xless than or =221). But the question says use poisson?How do i do it the poisson way?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Sep 2008
    From
    West Malaysia
    Posts
    1,261
    Quote Originally Posted by CautionItsHot View Post
    A manufacturer of rockets estimates that on average 1 in 75 of the rockets fail to burn properly.Using this estimate, and a Poisson distribution, find an approximate value for the probability that out of 225 randomly chosen rockets at most 221 burn properly.

    How do i solve this question using poisson distribution? I solve this question using binomial dist, using X~B(225,74/75) P(Xless than or =221). But the question says use poisson?How do i do it the poisson way?
    Edit:

    We will need to adjust the mean first. If there is 1 defective rocket in 75 rockets, there will be 3 defective rockets in 225 rockets. Also, it's the same as calculating the probability of at least 4 rockets did not properly burn, P(x>=4) with the poisson mean of 3.
    Last edited by mathaddict; November 4th 2010 at 06:02 AM.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Oct 2010
    Posts
    4
    I dun think your method, which is 1-P(X<=3) using 1/75 as the mean , will get the correct ans which is 0.353. Am i wrong?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Sep 2008
    From
    West Malaysia
    Posts
    1,261
    Quote Originally Posted by CautionItsHot View Post
    I dun think your method, which is 1-P(X<=3) using 1/75 as the mean , will get the correct ans which is 0.353. Am i wrong?
    Sorry, it was a mistake. I have edited my post.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 27th 2011, 01:08 PM
  2. Poisson distribution and asymptotic normal distribution.
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: August 18th 2010, 05:52 AM
  3. Poisson Distribution
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: November 10th 2009, 12:02 AM
  4. Poisson Distribution
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 8th 2009, 10:02 AM
  5. Poisson Distribution HELP!!!
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: January 7th 2009, 04:06 AM

Search Tags


/mathhelpforum @mathhelpforum