Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Binomial distribution of children

  1. Mar 10, 2009 #1
    I'm trying to figure out this problem but i keep getting stuck.

    The problem statement, all variables and given/known data

    A woman wants to have a 95% chance for a least a one boy and at least one girl. What is the minimum number of children that she should plan to have? Assume that the event that a child is a girl and a boy is equiprobable and independent of the gender of the other children born in the family.

    Relevant equations

    So i know you should use Pr(K = k) = (n\choose k)p^k(1-p)^(n-k)

    The attempt at a solution

    since the it's a 95% chance Pr(K=k)= .95
    probability of a boy or girl is 50% so it's .5

    .95= (n\choose k).5^k(1-.5)^(n-k)
    but then how would you solve or find what n and k is?
    Am i missing something here?

    Can anyone help! thank you in advance.
     
  2. jcsd
  3. Mar 10, 2009 #2
    In other words the probability of n children being either all boys or all girls is less than 5%.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Binomial distribution of children
  1. Binomial distribution (Replies: 2)

  2. Binomial distribution (Replies: 3)

  3. Binomial Distribution (Replies: 1)

  4. Binomial distribution (Replies: 3)

  5. Binomial distribution (Replies: 1)

Loading...