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    For the third part

    I know that 1 - Pr(0 Failures) = 0.5

    How do I find N and u

    Thanks
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    (Original post by khanpatel321)

    For the third part

    I know that 1 - Pr(0 Failures) = 0.5

    How do I find N and u

    Thanks
    Go to the definition of the Poisson, what's P(X=0) in terms of the parameter for the Poisson? Slap it into your equation and ...

    Then since 30,000 has a parameter of 0.3, what value (N) would give this parameter (the one you just worked out).
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    (Original post by khanpatel321)


    For the third part

    I know that 1 - Pr(0 Failures) = 0.5

    How do I find N and u

    Thanks

    May I ask where you got that worksheet from?
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    Let X = number of catastrophic failures in a production with N assemblies

    So, u is just the mean, or expected value: all you have to do is multiply N by 1/100000.
    >> u = (1x10-5)N
    Therefore:
    X ~ Po[(1x10-5)N]

    Now, to find N, we are told that P(X >= 1) = 0.5.
    But, P(X >= 1) = 1 - P(X = 0)
    Now this is were your Core maths skills come in handy as it begins to get a bit messy:
    image

    Forgot to round to 4 sig figs, sorry
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    (Original post by ghostwalker)
    Go to the definition of the Poisson, what's P(X=0) in terms of the parameter for the Poisson? Slap it into your equation and ...

    Then since 30,000 has a parameter of 0.3, what value (N) would give this parameter (the one you just worked out).

    (Original post by FusionNetworks)
    Let X = number of catastrophic failures in a production with N assemblies

    So, u is just the mean, or expected value: all you have to do is multiply N by 1/100000.
    >> u = (1x10-5)N
    Therefore:
    X ~ Po[(1x10-5)N]

    Now, to find N, we are told that P(X >= 1) = 0.5.
    But, P(X >= 1) = 1 - P(X = 0)
    Now this is were your Core maths skills come in handy as it begins to get a bit messy:
    image

    Forgot to round to 4 sig figs, sorry



    Thanks for that. Here is another similar question I get 3.5 days for the last part is this correct. Sorry no mark scheme available

    (Original post by Carolinec1206)
    May I ask where you got that worksheet from?
    Examples for an introduction to probability course at uni.
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    (Original post by khanpatel321)
    Here is another similar question I get 3.5 days for the last part is this correct.
    Agreed.
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    (Original post by ghostwalker)
    Agreed.
    Thanks
 
 
 
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