Results 1 to 2 of 2

Math Help - confidence interval

  1. #1
    Newbie
    Joined
    Oct 2010
    Posts
    15

    confidence interval

    4) for over 20 years the occupational safety & health administration has required companies that handle hazardous chemicals to complete material safety data sheets (MSDSs) . These MSDSs have been criticized for being too hard to understand and complete by workers . Although improvements were implemented in 1990 , a more recent study of 150 MSDSs revealed that only 11% were satisfactorily completed ( chemical & Engineering news , Feb 7 , 2005 ).

    a) give a point estimate of p , the true proportion of MSDSs that are satisfactorily completed.
    b) Find a 95 % confidence interval for p
    c) Give a practical interpretation of the interval , part b
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Master Of Puppets
    pickslides's Avatar
    Joined
    Sep 2008
    From
    Melbourne
    Posts
    5,236
    Thanks
    28
    Quote Originally Posted by ekbio View Post
    a) give a point estimate of p , the true proportion of MSDSs that are satisfactorily completed.
    \hat{p} = \frac{x}{n}<br />

    Quote Originally Posted by ekbio View Post
    b) Find a 95 % confidence interval for p
    \displaystyle\hat{p}\pm Z_{\frac{\alpha}{2}}\times \sqrt{\frac{\hat{p}(1-\hat{p})}{n}}

    Quote Originally Posted by ekbio View Post
    c) Give a practical interpretation of the interval , part b
    The true proportion can be found in 95 out of 100 intervals constructed.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Confidence Interval
    Posted in the Statistics Forum
    Replies: 5
    Last Post: February 9th 2011, 10:51 PM
  2. confidence interval
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 31st 2011, 12:02 PM
  3. Confidence Interval
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: November 28th 2009, 02:50 PM
  4. confidence level and confidence interval?
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: July 12th 2009, 06:59 AM
  5. Confidence Interval
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 22nd 2008, 06:55 PM

Search Tags


/mathhelpforum @mathhelpforum