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Math Help - critical value

  1. #1
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    critical value

    for normal hypothesis testing
    1% level 1-tailed critical value of z = 2.326
    2.531 > 2.236 so significant
    i dont understand how they got 2.326
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  2. #2
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    Re: critical value

    we need more information than that to reprodruce the 2.326. Post the entire question and the working (if known) to get the answer.
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  3. #3
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    Re: critical value

    The farmer also grows onions. The weight in kilograms of the onions is Normally distributed
    with mean 0.155 and variance 0.005. He is trying out a new variety, which he hopes will yield
    a higher mean weight. In order to test this, he takes a random sample of 25 onions of the new
    variety and finds that their total weight is 4.77 kg. You should assume that the weight in kilograms
    of the new variety is Normally distributed with variance 0.005.

    Carry out the test at the 1% level.


    Mean weight = 4.77/25 = 0.1908
    test statistic= (0.1908-0.155)/sqrt(0.005)*sqrt(25)=2.531

    1% level 1-tailed critical value of z = 2.326
    2.531 > 2.236 so significant.
    There is sufficient evidence to reject H0
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  4. #4
    MHF Contributor Siron's Avatar
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    Re: critical value

    Are you allowed to use a calculator(Ti-83?)? With 1-PropZtest you can compare the given p-value with the significance level (1%).
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  5. #5
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    Re: critical value

    The farmer also grows onions. The weight in kilograms of the onions is Normally distributed
    with mean 0.155 and variance 0.005. He is trying out a new variety, which he hopes will yield
    a higher mean weight. In order to test this, he takes a random sample of 25 onions of the new
    variety and finds that their total weight is 4.77 kg. You should assume that the weight in kilograms
    of the new variety is Normally distributed with variance 0.005.

    Carry out the test at the 1% level.


    Mean weight = 4.77/25 = 0.1908
    test statistic= (0.1908-0.155)/sqrt(0.005)*sqrt(25)=2.531

    1% level 1-tailed critical value of z = 2.326
    2.531 > 2.236 so significant.
    There is sufficient evidence to reject H0
    sorry, i misread your first post. The 2.326 is the upper 99% point on the normal distribution. You are doing a 1-tailed 1% test so you should look at the 99% point.
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