1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Probability Interval, statistics help

  1. Jul 17, 2011 #1
    Probability Interval, statistics help!!

    1. The problem statement, all variables and given/known data
    Assume that the population is normal with mean of 90 and standard deviation of 25. A sample of size 100 will be selected.
    a.) What is your best estimate for the value of the sample mean?
    b.) What is the value of the standard error?
    c.) In the 95% probability interval for the sample mean, what is the value of the margin of error?
    d.) Construct the 95% center probability interval for the sample mean. (Give lower limit (LL) and upper limit (UL).


    2. Relevant equations
    (work shown below)


    3. The attempt at a solution
    4a.) 90
    4b.) 25 / (100)^1/2 = 25/10 = 5/2
    4c.) 1.96 * (5/2) = 4.9
    4d.) LL= 90 – 4.9 = 85.1
    UL= 90 + 4.9 = 94.9
    (84.1, 94.9)
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
    Last edited: Jul 17, 2011
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?



Similar Discussions: Probability Interval, statistics help
Loading...