Results 1 to 2 of 2

Math Help - 3 stat problems

  1. #1
    StatMan2007
    Guest

    3 stat problems

    1. x1 = 14, n1 = 20, x2 = 8, n2 = 20; right-tailed test, alpha = 0.05; 90% confidence interval

    2. Of 21,300 men who had not had a vasectomy, 69 were found to have prostate cancer, of 22,000 men who had a vasectomy, 113 were found to have prostate cancer.
    a. At the 1% sig level, do the data provide sufficient evidence to conclude that men who have had a vasectomy are at greater risk of having prostate cancer?
    b. Is this study a designed experiment or an observational study? Explain your answer.
    c. In view of your answers to part a and b, could you reasonably conclude that having a vasectomy causes an increased risk of prostate cancer? Explain your answer.

    3. Independent random samples of white and african-american elderly (aged 70 or older). Of the 4989 white elderly surveyed, 529 had at least once stroke, whereas 103 of the 906 african-american elderly surveyed reported at least one stroke. At the 5% sig level do the data suggest that there is a difference in stroke incidence between white and african-american elderly? Find and interpret a 95% con interval for the dif between white and african-american elderly.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,111
    Thanks
    2
    Those are nice problems. Perhaps you could demonstrate SOME understanding of the solutions.

    Can you define a Null Hypothesis?
    Can you differentiate between 1-tail and 2-tail tests?
    Do you know when to use a t-statistic vs. a z-statistic?
    What is the role of a "Critical Value"?
    What is a "Rejection Region" and how does it work?

    Help us out, here. I'm guessing you already have a textbook and a teacher. Will it REALLY help if we repeat what you know already? For this reason, please demonstrate what you know already.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. density for order stat, sufficient stat, MLE question
    Posted in the Advanced Statistics Forum
    Replies: 13
    Last Post: March 14th 2011, 01:50 AM
  2. t-stat
    Posted in the Statistics Forum
    Replies: 0
    Last Post: December 10th 2010, 07:44 PM
  3. stat Q
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: March 1st 2009, 10:00 AM
  4. Stat Help
    Posted in the Statistics Forum
    Replies: 0
    Last Post: March 12th 2008, 07:03 AM
  5. Couple stat. problems.
    Posted in the Statistics Forum
    Replies: 3
    Last Post: June 26th 2006, 12:58 PM

Search Tags


/mathhelpforum @mathhelpforum