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

jesusfreak Group Title

the principal will randomly choose 6 students from a large school to represent the school in a newspaper photograph. the probability that a chose student is an athlete is 30%. (assume that this doesn't change) What is the probability that 4 athletes are chosen?

  • 2 years ago
  • 2 years ago

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

    Is this for a statistics class, or something like algebra?

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

    Algebra 2

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

    YTheManifold: that's not actually correct because you're not including the degree of freedom that any 4 can be chosen

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

    Would you like to see what the possible answers could be?

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

    Sorry \[ {6\choose 4}\cdot 0.3^4\cdot 0.7^2 \] of course

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

    .3^4 * .7^2 is the p^k and p^(n-k) but you need the (6 choose 4) as well.

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

    the formula YTheManifold just posted is correct - can you compute that, jesusfreak?

    • 2 years ago
  8. cwrw238 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yes - this a Binomial Probability distribution

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

    the general form is (n choose k) * p^k * p^(n-k). (typo in the previous one)

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

    It all looks like gibberish. I have no idea what to do.

    • 2 years ago
  11. jesusfreak Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    The answers it gives is 0.05, 0.06, 0.07, 0.08

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

    OK, let's go through it step by step. Do you know how to compute .3^4?

    • 2 years ago
  13. cwrw238 Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    th 6 4 part means the number combinations of 4 from 6

    • 2 years ago
  14. jesusfreak Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah it's 81

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

    You forgot the decimal -- it's 0.3^4 we're computing. Then multiply that by 0.7^2.

    • 2 years ago
  16. jesusfreak Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    ok it equals .003969

    • 2 years ago
  17. ktklown Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    yes! Now you just need to multiply that by the (6 4) part, and you'll be done. That's called a "binomial". It's pronounced "6 choose 4", which means, if you have 6 things, how many ways can you choose 4 of them?

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

    There's a formula for computing that, but a lot of people just type it into a calculator - it's 15 in this case.

    • 2 years ago
  19. ktklown Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    The formula is n! / ( k! * (n-k)! )

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

    Anyway so in this case just multiply 15 * .3^4 * .7^2 and that's your answer.

    • 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.