+ Reply to Thread
Results 1 to 4 of 4

Thread: Large Sample Confidence Interval for the Mean - Problem is it right ???

  1. #1
    Points: 86, Level: 1
    Level completed: 72%, Points required for next Level: 14

    Location
    Cypress, TX
    Posts
    7
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Large Sample Confidence Interval for the Mean - Problem is it right ???




    The president of Jones Bank asked his research team to determine the average waiting time for its customer. A study of 100 customers was conducted with the following results: mean = 19.8 standard deviation = 2.06 minutes
    Prepare the 95% confidence interval for average waiting time...

    mean = 19.8
    standard deviation = 2.06 minutes
    sample / n = 100
    95% confidence interval = 1.96

    standard error = 2.06/sqrt 100 = 2.06/10 = .206

    19.8 +/- 19.96 (.206)

    19.8 +/- 0.40376

    19.39 less than or equal to u less than or equal to 20.20

    Jones Bank can be 95% confident that the average waiting time for customers is between 19.39 and 20.20

  2. #2
    Omega Contributor
    Points: 38,334, Level: 100
    Level completed: 0%, Points required for next Level: 0
    hlsmith's Avatar
    Location
    Not Ames, IA
    Posts
    6,998
    Thanks
    398
    Thanked 1,186 Times in 1,147 Posts

    Re: Large Sample Confidence Interval for the Mean - Problem is it right ???

    Seems right. You have some typos and the true definition of CI is a little different from what you have.


    I would write:


    Jones bank average wait time is 19.8 (95% CI: 19.39, 20.20).
    Stop cowardice, ban guns!

  3. #3
    TS Contributor
    Points: 12,227, Level: 72
    Level completed: 45%, Points required for next Level: 223
    rogojel's Avatar
    Location
    I work in Europe, live in Hungary
    Posts
    1,470
    Thanks
    160
    Thanked 332 Times in 312 Posts

    Re: Large Sample Confidence Interval for the Mean - Problem is it right ???

    However,
    Jones Bank should be made aware that waiting times are generally left skewed, so the mean might not be a good measure....

  4. #4
    Points: 86, Level: 1
    Level completed: 72%, Points required for next Level: 14

    Location
    Cypress, TX
    Posts
    7
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Smile Re: Large Sample Confidence Interval for the Mean - Problem is it right ???


    Thanks so much for answering my questions I am so grateful for your help...

+ Reply to Thread

           




Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts






Advertise on Talk Stats