Results 1 to 2 of 2

Math Help - Normal Distribution

  1. #1
    Newbie
    Joined
    Jan 2009
    Posts
    9

    Normal Distribution

    I know how to find out the probability within a given range on the normal distribution curve, but a textbook suddenly asked about finding the mean.

    There's an unknown mean and a standard deviation of 0.6. I have to calculate the mean if the values after 5.7 have a probability of 0.14.

    The answer is obviously provided in the textbook, but that's all there is. A step-by-step procedure would be awesome. Thanks in advance.
    Last edited by Lupin; January 15th 2009 at 12:48 AM.
    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 Lupin View Post
    I know how to find out the probability within a given range on the normal distribution curve, but a textbook suddenly asked about finding the mean.

    There's an unknown mean and a standard deviation of 0.6. I have to calculate the mean if the values after 5.7 have a probability of 0.14.

    The answer is obviously provided in the textbook, but that's all there is. A step-by-step procedure would be awesome. Thanks in advance.
    Pr(X > 5.7) = 0.14.

    Find the value z* of Z such that Pr(Z > z*) = 0.14.

    From Z = \frac{X - \mu}{\sigma} it follows that:

    z* = \frac{5.7 - \mu}{0.6}.

    Substitute your value of z* and solve for \mu.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 1
    Last Post: December 27th 2011, 01:08 PM
  2. normal distribution prior and posterior distribution proof
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: March 9th 2011, 06:12 PM
  3. Replies: 2
    Last Post: March 29th 2010, 02:05 PM
  4. Replies: 3
    Last Post: February 6th 2009, 03:59 AM
  5. Replies: 1
    Last Post: April 20th 2008, 06:35 PM

Search Tags


/mathhelpforum @mathhelpforum