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Math Help - Statistics help please

  1. #1
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    Statistics help please

    Can someone help me with this problem Im not sure if I am supposed to use a mean or a porprotion I think i am supposed to use a porprotion with this question but how do I find out my null and alternative hypothesis.... I dont want you guys to do the problem for me I just would like help starting it..

    Heres the question
    A company claims to have invented a hand-held sensor that can detect the presence of explosives inside a closed container. Law enforcement and security agencies are very interested in purchasing several of the devices if they are shown to perform effectively. An independent laboratory arranged a test. They placed four empty boxes in the corners of an otherwise empty room. For each trial they put a small quantity of an explosive in one of the boxes selected at random. The company’s technician then entered the room and used the sensor to try to determine which of the four boxes contained the explosive. The experiment consisted of 50 trials, and the technician was successful in finding the explosive 16 times. Does this indicate that the device is effective in sensing the presence of explosives? Test an appropriate hypothesis and state your conclusion. Find and interpret a 90% confidence interval.
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  2. #2
    Grand Panjandrum
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    Quote Originally Posted by starry eyes View Post
    Can someone help me with this problem Im not sure if I am supposed to use a mean or a porprotion I think i am supposed to use a porprotion with this question but how do I find out my null and alternative hypothesis.... I dont want you guys to do the problem for me I just would like help starting it..

    Heres the question
    A company claims to have invented a hand-held sensor that can detect the presence of explosives inside a closed container. Law enforcement and security agencies are very interested in purchasing several of the devices if they are shown to perform effectively. An independent laboratory arranged a test. They placed four empty boxes in the corners of an otherwise empty room. For each trial they put a small quantity of an explosive in one of the boxes selected at random. The company’s technician then entered the room and used the sensor to try to determine which of the four boxes contained the explosive. The experiment consisted of 50 trials, and the technician was successful in finding the explosive 16 times. Does this indicate that the device is effective in sensing the presence of explosives? Test an appropriate hypothesis and state your conclusion. Find and interpret a 90% confidence interval.
    The null hypothesis is that the sense is no better than random, so the
    number of trials in which the explosive is found is ~B(50,0.25).

    The alternative is that the sensor is better than random and the number
    of successes is ~B(50,p), with p>0.25.

    RonL
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  3. #3
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    Nov 2007
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    one more question

    So do you know which type of test I use for this problem
    as in (one-proportion z-test or interval, two-proportion z-test or interval, t-test or interval, two-sample t-test or interval, or paired t-test or interval)
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