Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Confucious

Consider a binomial experiment with n trials for which np>5 and nq>5. What is the value of the continuity correction when n=25; when n=230? Round answer to 3 decimal places.

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    As the value of n increases, does the continuity correction value increase, decrease, or stay the same?

    • 2 years ago
  2. Ishaan94
    Best Response
    You've already chosen the best response.
    Medals 0

    Why did you close it?

    • 2 years ago
  3. Ishaan94
    Best Response
    You've already chosen the best response.
    Medals 0

    I don't know how to do it, but Zarkon, nikvist and KingGeorge are online, you can either repost it or tag them on this thread.

    • 2 years ago
  4. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    i had to so tht i could post another question, how do i tag them?

    • 2 years ago
  5. Ishaan94
    Best Response
    You've already chosen the best response.
    Medals 0

    Using '@' Example: @Confucious

    • 2 years ago
  6. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    thanks

    • 2 years ago
  7. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    @Hero @Zarkon @KingGeorge

    • 2 years ago
  8. Hero
    Best Response
    You've already chosen the best response.
    Medals 0

    I don't know how to do this either, sorry

    • 2 years ago
  9. Hero
    Best Response
    You've already chosen the best response.
    Medals 0

    Ask Satellite, Myininaya, JamesJ or amistre64

    • 2 years ago
  10. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    k thanks

    • 2 years ago
  11. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Can you give me a rundown of what the continuity correction is?

    • 2 years ago
  12. Hero
    Best Response
    You've already chosen the best response.
    Medals 0

    I've never even heard of continuity correction. What course is this?

    • 2 years ago
  13. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Definitely some kind of statistics course.

    • 2 years ago
  14. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    From what I've found on wikipedia, if you use a continuity correction of 0.500 you almost always get a good approximation. But I don't think this is what you want.

    • 2 years ago
  15. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    My txtbk says that the continuity correction is for the upper and lower endpoints of an interval, this question doesn't have any about an interval there, that's why I don't know what to do with it.

    • 2 years ago
  16. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    I think I have it. According to the bottom of page 313 of http://books.google.com/books?id=kNutPR9P3hoC&pg=PA313&lpg=PA313&dq=how+to+find+the+continuity+correction&source=bl&ots=EioM54saDN&sig=1nJZqwxIBC2UHYbFHfWzp_qZcSU&hl=en&sa=X&ei=sHV7T_nmJKq22gXd07CIAw&ved=0CE8Q6AEwBg#v=onepage&q&f=false, the continuity correction should be\[{0.5 \over n}\]So for your numbers...\[{0.5 \over 25}\approx0.020\]\[{0.5 \over 230}\approx0.002\]

    • 2 years ago
  17. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    So if \(n\) increases, continuity correction decreases.

    • 2 years ago
  18. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    ...I'll try this. Thank you so much.

    • 2 years ago
  19. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    You're welcome.

    • 2 years ago
  20. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    Look at this one please. Suppose we have a binomial distribution with n trials and probability of success p. The random variable r is the number of successes in the n trials, and the random variable representing the proportion of successes is = r/n. (a) n = 51; p = 0.45; Compute P(0.30 ≤ ≤ 0.45). (Round your answer to four decimal places.) (b) n = 49; p = 0.29; Compute the probability that will exceed 0.35. (Round your answer to four decimal places.)

    • 2 years ago
  21. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    I have 0.006 </= p-hat </= 0.009 but that looks completely wrong.

    • 2 years ago
  22. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Judging by what the previous question was, I would assume we need to find the continuity correction again which is \[{0.5 \over 51}\approx0.0098\]and add/subtract this to the interval \([0.3, 0.45]\). So it becomes \(0.2902 \leq \hat p \leq 0.4598\) Using a normal distribution.

    • 2 years ago
  23. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Looking at the example in the book I linked to, we also need to calculate the standard deviation which would be \[\sigma_{\hat p} = \sqrt{pq \over n}=\sqrt{.45(.55) \over 51} \approx0.3518\]

    • 2 years ago
  24. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Still going from the example, we just need to find\[P\left( {.2902-.45 \over .3518} \leq z \leq {.4598 -.45 \over .3518} \right)\]Where \(z\) is that variable thing you use for the normal distribution.

    • 2 years ago
  25. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Simplifying a bit, we get\[P\left( -.4542 \leq z\leq .0279 \right)\]

    • 2 years ago
  26. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Which I get to be about \(P\approx 0.1863\)

    • 2 years ago
  27. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    I got a different answer for the standard deviation. It's 0.0697.

    • 2 years ago
  28. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    How did you calculate the standard deviation?

    • 2 years ago
  29. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    I'm going almost entirely by what that book I linked to is telling me.

    • 2 years ago
  30. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    That's the textbook I'm using but a newer edition that doesn't have some of this stuff and to find z it's (x minus the mean) over the standard deviation. We don't have the mean.

    • 2 years ago
  31. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    According to the book\[\mu_{\hat p} = p=0.45\]Which is what I was using for the mean

    • 2 years ago
  32. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    But you are correct about the standard deviation. I was using \(n=2\) for some reason. I now have \[\sigma_{\hat p} \approx 0.0697\]

    • 2 years ago
  33. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    If we recalculate using that, we want\[P\left( {0.2902-0.45 \over 0.0697} \leq z\leq {0.4598 -.45 \over 0.0697} \right)\]\[\approx P\left( -2.2927 \leq z \leq 0.1406 \right)\]

    • 2 years ago
  34. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    oh yh

    • 2 years ago
  35. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Which finally gets us that \[P\approx 0.5449\]

    • 2 years ago
  36. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    And that was just for part a.

    • 2 years ago
  37. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    For the z scores, they have to be rounded to 2 decimal places and then we find the probability from a table giving the areas of the standard normal distribution. From that I got 0.5447. How did you get 0.5449?

    • 2 years ago
  38. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    I was using all 4 decimal places and my calculator. If you're using the table and 2 decimal places, go with 0.5447

    • 2 years ago
  39. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    Okay. We find the continuity correction again for part (b) right?

    • 2 years ago
  40. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    yup.

    • 2 years ago
  41. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    But here's the thing. There's no interval so I don't know if I should add or subtract.

    • 2 years ago
  42. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Use the interval \[P\left(.35\leq \hat p\leq 9\times 10^{99}\right)\] Or a similar upper bound.

    • 2 years ago
  43. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    ??? why???

    • 2 years ago
  44. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Just make it so large that it doesn't matter what you do. At values that high, the sum of the probabilities greater than \(9\times 10^{99}\) is small that it might as well be 0.

    • 2 years ago
  45. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Although you said you have to use a chart and not a calculator. That might complicate things.

    • 2 years ago
  46. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    I don't get that. How can that number be used. It looks like it's too big to be even written out.

    • 2 years ago
  47. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    We can use it because the probability that \(z \geq 10^{99}\) is virtually \(0\). So really, we're dealing with 0.

    • 2 years ago
  48. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    so it can be \[P(0.35\le p-\hat \le 0)\] ? [I don't know why it came out like that]

    • 2 years ago
  49. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Let's just forget I said we could do that for the moment, and continue with the actual problem (we'll come back to it soon). That means that the continuity correction is \[{0.5\over49}\approx0.0102\]Also, \[\mu_{\hat p} =0.29\]\[\sigma_{\hat p} \approx 0.0648\]Feel free to check my work.

    • 2 years ago
  50. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Thus, we need to find\[P\left({.3398-.35 \over .0648} \leq z \right)\]or\[P\left( -0.1574 \leq z \right)\]

    • 2 years ago
  51. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    where did you get .3398 and -0.1574 from??

    • 2 years ago
  52. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    I subtracted the continuity correction from the lower interval to get .3398 .3398=.35-0.0102

    • 2 years ago
  53. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    And \[{.3398-.35 \over 0.648} \approx -0.1574\]

    • 2 years ago
  54. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Now let's get back to what we were talking about previously. How were you taught to find \[P(-0.1574 \leq z)?\]

    • 2 years ago
  55. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    the text has a table in it that gives all the probabilities to the left of a z score from -3.49 to 3.49. Once we find the z score, we round it to 2 decimal places (because that's how the table has it) and we find it on the table and take the probability that's there for the answer.

    • 2 years ago
  56. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Then you want to find the probability for \(z=-0.16\) and subtract it from 1.

    • 2 years ago
  57. KingGeorge
    Best Response
    You've already chosen the best response.
    Medals 2

    Sorry if I'm sounding angry or impatient, I'm really not :) I do need to leave for dinner now though. I'm getting an overall probability of about 0.5625. If you're very close to this, just assume you're correct.

    • 2 years ago
  58. Confucious
    Best Response
    You've already chosen the best response.
    Medals 0

    ok thanks a lot for your help

    • 2 years ago
    • Attachments:

See more questions >>>

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.