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

radh

Statistics help?

  • one year ago
  • one year ago

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

    Grades can be converted into numbers (as in calculating a GPA) where an A = 4, B = 3, C = 2, D = 1, and F = 0. For a fictional class, the grade distribution was: X(Grade) 4 3 2 1 0 P(X) 0.20 0.25 0.30 0.10 0.15 a) Verify that this is a legitimate probability distribution. b) Find the mean grade for this class. c) Find the standard deviation

    • one year ago
  2. lilfayfay
    Best Response
    You've already chosen the best response.
    Medals 0

    wrong section

    • one year ago
  3. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    openstudy has a stats section?

    • one year ago
  4. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    could u do part a) ?

    • one year ago
  5. lilfayfay
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah

    • one year ago
  6. lilfayfay
    Best Response
    You've already chosen the best response.
    Medals 0

    at the top it will say "Find More Subjects"

    • one year ago
  7. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah, I know part a. It's legitimate because the total probability is equal to 1.

    • one year ago
  8. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    good, thats correct. where r u stuck ?

    • one year ago
  9. lilfayfay
    Best Response
    You've already chosen the best response.
    Medals 0

    Yeah its at the very bottom if you click on "Find More Subjects" at the top :))

    • one year ago
  10. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    finding the mean/sd. i found those out, but idk how to corrleate them with the grades. i know mean is .2, so would that mean the average grade is 4 because its' probability is .2?

    • one year ago
  11. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    oh, whoops. i didn't see that before. i'll go there next time.

    • one year ago
  12. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    mean is 0.2 ? which formula did u use ?

    • one year ago
  13. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    total is 1, divided by 5, .2? did i do that wrong?

    • one year ago
  14. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    yes... Mean = \(\sum xP(x)\) so, it will be mean = 0.2*4 + 0.25*3 + ......

    • one year ago
  15. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    oooh. okay. one sec. let me calculate that. :P

    • one year ago
  16. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    2.25?

    • one year ago
  17. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    don't u have answers to verify ?

    • one year ago
  18. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah, even i get 2.25

    • one year ago
  19. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    nope. answers are given upon completion. :P

    • one year ago
  20. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    but thanks, I think I got it now. Wrong formula. :P

    • one year ago
  21. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    and u know formula for sd ?

    • one year ago
  22. radh
    Best Response
    You've already chosen the best response.
    Medals 1

    yeah, got that. i compared that with a friend, and she got the same answer. it was just the mean.

    • one year ago
  23. hartnn
    Best Response
    You've already chosen the best response.
    Medals 1

    ok, good :)

    • one year ago
  24. hanban1
    Best Response
    You've already chosen the best response.
    Medals 0

    hartnn, if you don't mind could you explain how to find the standar deviation, i'm a bit confused on how to go about it.

    • one year 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.