Results 1 to 2 of 2

Math Help - statistic problem

  1. #1
    Newbie
    Joined
    May 2008
    Posts
    5

    statistic problem

    I am having trouble on how to work this problem. Any help would be appreciated. Thanks in advance.

    5. The Bridgestone Bicycle Company purchases bicycle chains from a third party supplier. The chains are required to be within 0.25” of 54 inches in order to work properly. If the chains are too slack or too tight the derailleur will not work correctly. The chains are supplied by the Ajax Manufacturing Company and the individual links are not exactly uniform. They fluctuate around a mean length of 0.5”, with a standard deviation of 0.01”.

    a) How many links should be strung together to form a chain?

    b) Based on the above data, what proportion of the chains would be expected to meet Bridgestone’s standards?




    c) Suppose Ajax Manufacturing Company wished to reduce the proportion of chains that failed to meet Bridgestone’s standards to one half of the current value, to what value would they have to change the standard deviation of the lengths of the individual chain links?




    d) Suppose that Ajax guarantees a 1% defective rate on the chains supplied to the Bridgestone Company, if it were found that 490 out of 500 randomly selected chains met Bridgestone’s expectations, do you think that Ajax is living up to its guarantee? Test the StatisticalHypothesis that the defective rate is 1% against the alternative that it is greater than 1%. Use a level of significance of 0.05.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by craminator66 View Post
    I am having trouble on how to work this problem. Any help would be appreciated. Thanks in advance.

    5. The Bridgestone Bicycle Company purchases bicycle chains from a third party supplier. The chains are required to be within 0.25” of 54 inches in order to work properly. If the chains are too slack or too tight the derailleur will not work correctly. The chains are supplied by the Ajax Manufacturing Company and the individual links are not exactly uniform. They fluctuate around a mean length of 0.5”, with a standard deviation of 0.01”.

    a) How many links should be strung together to form a chain?
    to get a chain with mean length 54" will require 108 half inch links, then length of a chain made of this many links will have a SD of \sigma_{chain}=\sqrt{108} \times 0.01 and because 108 is a reasonably large number may the length may be treated as though it were normaly distributed with mean 54" and SD \sigma_{chain}.

    That should allow you to answer the rest of these questions.

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. help with statistic problem
    Posted in the Statistics Forum
    Replies: 5
    Last Post: November 17th 2010, 09:26 PM
  2. statistic problem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: March 2nd 2010, 09:05 AM
  3. please help me on this statistic problem
    Posted in the Statistics Forum
    Replies: 5
    Last Post: December 31st 2009, 05:12 AM
  4. PLEASE PLEASE help with this statistic problem!
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: March 7th 2009, 03:01 PM
  5. Statistic Problem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 7th 2009, 04:45 AM

Search Tags


/mathhelpforum @mathhelpforum