Results 1 to 2 of 2

Math Help - Normal Distribution problem

  1. #1
    Newbie
    Joined
    Mar 2010
    Posts
    3

    Normal Distribution problem

    A factory has a machine designed to produce 1 kg bags of sugar. It is found that the average weight of sugar in the bags is 1.02 kg. Assuming that the weights of the bags are normally distributed, find the standard deviation if 1.7% of the bags weigh below 1 kg.
    Give your answer correct to the nearest 0.1 gram.
    I know how to find the percentage by using mean and standard deviation, but I do not understand how to get standard deviation from just the mean and percentage. Please help, it would be greatly appreciated.
    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 Shadow2793 View Post
    , but I do not understand how to get standard deviation from just the mean and percentage. Please help, it would be greatly appreciated.
    Let's say P(z<a)=0.017

    By the normal distribution table P(z<-2.1201)=0.017

    And

     -2.1201=\frac{X-\mu}{\sigma}

    Can you finish it off?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. A Normal Distribution Problem
    Posted in the Statistics Forum
    Replies: 3
    Last Post: December 13th 2010, 02:04 PM
  2. A Normal Distribution Problem
    Posted in the Statistics Forum
    Replies: 1
    Last Post: December 12th 2010, 09:18 PM
  3. Another normal distribution problem
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: February 27th 2009, 10:11 PM
  4. Normal Distribution Problem.
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: September 7th 2008, 12:28 AM
  5. Normal Distribution Problem
    Posted in the Advanced Statistics Forum
    Replies: 4
    Last Post: April 17th 2008, 11:04 AM

Search Tags


/mathhelpforum @mathhelpforum