Results 1 to 3 of 3

Math Help - one more for statistics

  1. #1
    Newbie
    Joined
    Jul 2008
    Posts
    3

    one more for statistics

    if anyone could please help with this it would be great.

    The mechanic at a manufacturing plant has made the claim that his machine will make, on average, no more than four defective parts per hour. Over a period of 16 hours, the machine makes an average of 4.6 defective parts per hour, with a standard deviation of .8 parts per hour. Test the mechanic's claim.

    thanks again to whomever can help.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    It is hoped that you can help. What have you done?

    Did you calculate the test statistic?

    Did you identify the Critical Region?

    What distribution are you supposing for the parameter you are estimating?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member
    Joined
    Mar 2008
    From
    Pennsylvania, USA
    Posts
    269
    Thanks
    37
    *sigh* another one of these...

    The mechanic at a manufacturing plant has made the claim that his machine will make, on average, no more than four defective parts per hour. Over a period of 16 hours, the machine makes an average of 4.6 defective parts per hour, with a standard deviation of .8 parts per hour. Test the mechanic's claim.


    H_0: u ≤ 4
    H_A: u > 4

    x = 4
    u = 4.6
    s = 0.8
    n = 16

    Personally, now, I would use a student's t-test to find the p-value, since n<30. However, I will do the set-up using the z-test statistic. If you need to change it, you are free to do so. The t-test follows almost the same pattern and guidelines.

    z = x-u / s(sqrt n)
    z = 4-4.6 / (0.8*sqrt16) = -0.6 / (0.8*4) = -0.6 / 3.2 = -0.1875

    The one-tailed p-value is 1 - 0.5743657 = 0.4256343. This is absurdly high and is well above the standard significance-level of 0.05. We fail to reject the null hypothesis.

    Good luck! If you can clarify this question any more, please do so.
    -Andy
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. pet statistics
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: April 11th 2009, 12:07 PM
  2. Statistics
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: April 1st 2009, 11:48 PM
  3. Statistics
    Posted in the Statistics Forum
    Replies: 1
    Last Post: April 1st 2009, 12:08 PM
  4. Statistics
    Posted in the Statistics Forum
    Replies: 5
    Last Post: February 3rd 2008, 07:55 AM
  5. statistics
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 21st 2007, 09:02 AM

Search Tags


/mathhelpforum @mathhelpforum