Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Confidence intervals

  1. Mar 15, 2006 #1
    What is the value of za/2 for an 80% confidence interval?
    a. .255.
    b. 1.28.
    c. .0398.
    d. .525.

    i know the answer is a, but does anyone know how to calculate that :blushing: ?
     
  2. jcsd
  3. Mar 16, 2006 #2

    HallsofIvy

    User Avatar
    Staff Emeritus
    Science Advisor

    Not in any easy manner- you look it up in a table!
    Here's one on the internet:
    http://people.hofstra.edu/faculty/Stefan_Waner/RealWorld/normaltable.html [Broken]
     
    Last edited by a moderator: Apr 22, 2017 at 8:55 AM
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Confidence intervals
  1. Confidence Intervals (Replies: 1)

  2. Confidence Interval (Replies: 1)

  3. Confidence Intervals (Replies: 0)

  4. Confidence intervals (Replies: 3)

  5. Confidence Interval (Replies: 4)

Loading...