Results 1 to 2 of 2

Thread: Probability Help

  1. #1
    Nov 2009

    Probability Help

    I have been sweating buckets over my recent statistics test on probability. It's not coming to me, and my textbook isn't helping me much. I am basically clueless on how to calculate sample size with no preliminary estimate.

    Here is the example I'm pouring over.

    You are a travel agent and wish to estimate, with 95% confidence, the proportion of vacationers who plan to travel outside the United States in the next 12 months. Your estimate must be accurate within 3% of the true proportion. Find the minimum sample size needed if no preliminary estimate is available.

    Any way I can get some help showing how to solve this problem? Any help is greatly appreciated.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Eater of Worlds
    galactus's Avatar
    Jul 2006
    Chaneysville, PA
    If no preliminary estimate is available, use p=q=.5

    n=pq\left(\frac{z}{E}\right)^{2}=(.5)(.5)\left(\fr  ac{1.96}{.03}\right)^{2}\approx 1067.11

    Round up and get 1068 as the minimum sample size.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 10
    Last Post: Jan 21st 2011, 12:47 PM
  2. Replies: 3
    Last Post: May 29th 2010, 08:29 AM
  3. Replies: 1
    Last Post: Feb 18th 2010, 02:54 AM
  4. Replies: 0
    Last Post: Jan 20th 2010, 07:04 AM
  5. Replies: 3
    Last Post: Dec 15th 2009, 07:30 AM

Search Tags

/mathhelpforum @mathhelpforum