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  1. #1
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    Smile help



    hello,

    I have the answer in the back of my book to this problem, but could not comprehend how they came up with this answer, any clarification is highly appreciated:


    local newspaper polls 400 voters in an attempt to predict whether the budget will pass. suppose that the badget actually has the support of 52% of the voters. what is the probability the newspapers's sample will lead them to predict defeat?

    their answer was 0.212

    i wonder how is the probability that i need tocalculate: is it the 48% who do not support the budget?

    thanks.

  2. #2
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    Hi,

    What the answer is working with is a random variable X~Binomial(400,0.52) and you have to work out the probability that X is less than 200 (or predicting that less than 50% will support it during the poll).

    You will need to use the Central Limit Theorem to do this, you're tables will not provide the answer.

    Give it a try and let me know if you have any problems,

    CJ

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