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Math Help - Dice Probability

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    Dice Probability

    A dice has 6 faces numbered 1-6. If I roll it 9 times what is the probability that I will get the number 4 exactly 6 times? Answer as a decimal accurate to at least 4 significant figures.
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    Quote Originally Posted by mr_motivator View Post
    A dice has 6 faces numbered 1-6. If I roll it 9 times what is the probability that I will get the number 4 exactly 6 times? Answer as a decimal accurate to at least 4 significant figures.
    The singular of dice is a die. So a die is rolled nine times.
    The probability of getting a 4 on any roll is \frac {1}{6}.
    In nine rolls there are 9 \choose 6 ways to get exactly six 4ís in six.
    {9 \choose 6}\left( {\frac{1}{6}} \right)^6 \left( {\frac{5}{6}} \right)^3
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  3. #3
    MHF Contributor matheagle's Avatar
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    Binomial distribution with n=9 and p=1/6.
    P(X=x)={9 \choose x}(1/6)^x(5/6)^{9-x}
    where x=0,1,...,9. Where you want x=6.
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