Results 1 to 7 of 7

Math Help - The following are average weakly losses of worker-hours

  1. #1
    Banned
    Joined
    Dec 2008
    From
    Mauritius
    Posts
    523

    The following are average weakly losses of worker-hours

    Question

    The following are average weakly losses of worker-hours due to accidents in 10 industrial plants before and after a certain safety program was put in operation :

    <br />
Before : \qquad 45 \qquad 73 \qquad 46 \qquad 124 \qquad 33 \qquad 57 \qquad 83 \qquad 34 \qquad 26 \qquad 17
    <br />
After : \ \  \qquad 36 \qquad 60 \qquad 44 \qquad 119 \qquad 35 \qquad 51 \qquad 77 \qquad 29 \qquad 24 \qquad 11<br />

    Use the 0.05 level of significance to test whether the safety program is effective.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by zorro View Post
    Question

    The following are average weakly losses of worker-hours due to accidents in 10 industrial plants before and after a certain safety program was put in operation :

    <br />
Before : \qquad 45 \qquad 73 \qquad 46 \qquad 124 \qquad 33 \qquad 57 \qquad 83 \qquad 34 \qquad 26 \qquad 17
    <br />
After : \ \ \qquad 36 \qquad 60 \qquad 44 \qquad 119 \qquad 35 \qquad 51 \qquad 77 \qquad 29 \qquad 24 \qquad 11<br />

    Use the 0.05 level of significance to test whether the safety program is effective.
    What have you done? What tests do you know for comparing 'before and after' data?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Banned
    Joined
    Dec 2008
    From
    Mauritius
    Posts
    523

    I dont know from where to start

    Quote Originally Posted by mr fantastic View Post
    What have you done? What tests do you know for comparing 'before and after' data?

    I dont know where to start , need ur guidance
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by zorro View Post
    I dont know where to start , need ur guidance
    But what tests have you learned in class? What do your class notes say? You must have learned tests for this sort of thing otherewise you wouldn't be given questions on it ....

    Try reading this thread: http://www.mathhelpforum.com/math-he...nce-level.html

    (Personally, without knowing more I'd use a non-parametric test).
    Last edited by mr fantastic; December 13th 2009 at 05:14 AM.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Banned
    Joined
    Dec 2008
    From
    Mauritius
    Posts
    523

    Which test should i use?

    Quote Originally Posted by mr fantastic View Post
    But what tests have you learned in class? What do your class notes say? You must have learned tests for this sort of thing otherewise you wouldn't be given questions on it ....

    Try reading this thread: http://www.mathhelpforum.com/math-he...nce-level.html

    (Personally, without knowing more I'd use a non-parametric test).


    Should i use the
    1) Test concerning the Mean
    or
    2)Test concerning the difference between the Mean

    please advice
    Last edited by zorro; December 16th 2009 at 01:44 AM.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Banned
    Joined
    Dec 2008
    From
    Mauritius
    Posts
    523

    Is this correct?

    Quote Originally Posted by zorro View Post
    Should i use the
    1) Test concerning the Mean
    or
    2)Test concerning the difference between the Mean

    please advice


    I am going to use this please advice me if i am doing it correctly or no !!!

    H_0 : \mu_1 - \mu_2 =0

    H_a : \mu_1 - \mu_2 < 0

    \alpha = 0.05

    <br />
t = \sum_{i=1}^{n} \frac{\bar x_1 - \bar x_2 - 0}{S_p \sqrt{\frac{1}{n_1} + \sqrt{1}{n_2}}}

    where S_p = \frac{(n_1 - 1)s_1 ^2 + (n_2 - 1) s_2 ^2}{n_1 + n_2 -2}
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Banned
    Joined
    Dec 2008
    From
    Mauritius
    Posts
    523

    Mr fantastic is this correct???

    Quote Originally Posted by mr fantastic View Post
    But what tests have you learned in class? What do your class notes say? You must have learned tests for this sort of thing otherewise you wouldn't be given questions on it ....

    Try reading this thread: http://www.mathhelpforum.com/math-he...nce-level.html

    (Personally, without knowing more I'd use a non-parametric test).

    My work

    H_0 : \mu_1 - \mu_2 = 0
    H_a : | \mu_1 - \mu_2 | > 0
    \alpha : 0.05

    Since a single tailed t_{0.05/2 , n_1+ n_2 -1} = t_{0.025,18}= 2.101........Is this correct????

    t = \frac{ \bar x - \bar y - 0}{S \sqrt{ \frac{1}{n_1} + \frac{1}{n_2}}}

    where S^2 = \frac{\sum(x- \bar x)^2 + \sum (y - \bar y)^2}{n_1 + n_2 -2}= 995.4...........Is this answer correct????

    \therefore t = 7.26

    since calculate value is 7.26 > 2.101 therefore the H_0 is rejected..................Is this procedure for solving the problem correct???
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. minimum losses...
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: October 20th 2011, 06:03 PM
  2. Weakly Cauchy
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: January 18th 2011, 09:30 AM
  3. convergence weakly/in-distribution
    Posted in the Advanced Statistics Forum
    Replies: 7
    Last Post: March 4th 2010, 03:04 PM
  4. Roulette’s chips distribution: Wins vs Losses
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: December 12th 2009, 08:03 PM

Search Tags


/mathhelpforum @mathhelpforum