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

Student's t- distribution to construct a confidence interval question

  1. Mar 9, 2012 #1
    The following are summary statistics for a data set. Would it be appropriate to use the
    Student's t- distribution to construct a confidence interval for these data?
    Explain clearly!

    Sample size = 10
    Mean = 8.905
    Median = 6.105
    Standard deviation = 9.690
    Minimum = 0.512
    Maximum = 39.920
    Q1 = 1.967
    Q3 = 8.103

    My answer would be it would be appropriate since n is less than 40(small sample size), we can use t distribution.

    Any other explanations guys
  2. jcsd
  3. Mar 9, 2012 #2

    Stephen Tashi

    User Avatar
    Science Advisor

    A confidence interval for what? The mean of the population they were sampled from?

    This is a homework type problem, right? We begin to see why homework section wants such problems posed in a orderly format that includes a complete statement of the problem.

    I suppose the issue here might be how much your numerical tables for the t-statistic depend on the population being normally distributed and whether you think your sample is.from a normally distributed population.
  4. Mar 9, 2012 #3
    thats right, and thats the data given in the question,

    the question says if it is suitable to use t distribution to construct a confidence interval using the given data.

    Somehow i have to explain how its possible?

    Any ideas?
  5. Mar 9, 2012 #4
    so Stephen, your suggesting its not suitable to use tdistribution because its not normally disstributed but could there be any other reasons?
  6. Mar 12, 2012 #5
    Joe, just simply look how t distribution looks. Is it symmetric? What about other properties? Do your data look like samples from this distribution? Etc.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook