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Math Help - probability question

  1. #1
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    probability question

    A dating service finds that 35% of the couples that it matches eventually get married. In the next 150 matches that the service makes, find the probability that at least 20 couples get married.

    this is the first time i come across this kind of question...i dun know thw way to handle it.....can anyone possibly help??

    Thx in advance.
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  2. #2
    Senior Member Danneedshelp's Avatar
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    Quote Originally Posted by littleprince327 View Post
    A dating service finds that 35% of the couples that it matches eventually get married. In the next 150 matches that the service makes, find the probability that at least 20 couples get married.

    this is the first time i come across this kind of question...i dun know thw way to handle it.....can anyone possibly help??

    Thx in advance.
    This sounds like a binomial problem.

    Let X denote the number of matched couples that eventually get married. Consequently, the random variable X has a binomial distribution based on n=150 trials with success probability p=0.35. It follows that,

    P(X\geq\\20)=\sum_{x=20}^{150}\left( \begin{array}{ccc}\\<br />
150\\ <br />
x\end{array} \right)\\(.35)^{x}(1-.35)^{150-x}.
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  3. #3
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    but how can i calculate the answers by calculator??
    the formula is so long...
    is there any other way which can solve the question simply?
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  4. #4
    Senior Member Danneedshelp's Avatar
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    Quote Originally Posted by littleprince327 View Post
    but how can i calculate the answers by calculator??
    the formula is so long...
    is there any other way which can solve the question simply?
    Binomial Calculator

    Binomial Distribution: Probability Calculator

    there are all kinds of calculators out there
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  5. #5
    MHF Contributor matheagle's Avatar
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    Your instructor most likely wants you to use the normal approximation to the binomial distribution.
    That's a central limit theorem that was proved by Gauss.
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