Results 1 to 3 of 3

Math Help - Finding the confidence interval given a population sample

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    104
    Thanks
    1

    Finding the confidence interval given a population sample

    I can't seem to figure out the second half of this question:

    Consider the sample 100 91 91 86 90 91 90 94 from a normal population with population mean μ and population variance σ2. Find the 95% confidence interval for μ.
    I know that μ = μ of sample = 91.625, but i need to find the range

    I also know the standard deviation of the sample of the population is σ/sqrt(n)

    the answer s 91.633.37 but I'm not sure where 3.37 comes from, since the σ the sample population is 4.03/sqrt(8) = 1.425
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Sep 2010
    Posts
    185
    Thanks
    13

    Re: Finding the confidence interval given a population sample

    One of the famous properties of normal distribution: interval μ plus/minus 2σ contains 95% of the values.

    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Sep 2009
    Posts
    104
    Thanks
    1

    Re: Finding the confidence interval given a population sample

    Thanks, but I just figured it out.. The formula I should be using for the margin of error is x-bar +/- t(a/2)*(σ/sqrt(n))
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 7
    Last Post: March 19th 2012, 07:39 PM
  2. Confidence Interval for population mean
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: June 5th 2010, 03:02 AM
  3. Confidence Interval for Population Standard Deviation
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: November 20th 2009, 08:47 AM
  4. confidence interval for cluster sample
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 2nd 2009, 05:48 PM
  5. Replies: 2
    Last Post: January 29th 2009, 07:23 AM

Search Tags


/mathhelpforum @mathhelpforum