Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

Libniz

  • 2 years ago

Let X be a discrete random variables with PMF given by : P_X(x)= x/15 ,{x=1,2,3,4,5} 0 , otherwise b)let Y=(X-3)^2, find range Y, S_Y , PMF of Y

  • This Question is Closed
  1. bahrom7893
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    @amistre64

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

    @Zarkon

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

    where are you stuck?

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

    P_X(x)= x/15 ,{x=1,2,3,4,5} 0 , otherwise so to find range using Y y= (X-3)^2 ((x/15)-3)^2 y= (1/15 -3)^2 (-44/45)^2 to 0

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

    am I right?

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

    no

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

    x takes the values 1,2,3,4,5 y=(x-3)^2 plug those x values into the above equation

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

    for the range(support)

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

    oh, it is X, not x

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

    yes...so X takes the values 1,2,3,4,5 Y=(X-3)^2 plug those X values into the above equation :)

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

    1 Attachment
  12. Zarkon
    • 2 years ago
    Best Response
    You've already chosen the best response.
    Medals 2

    ok...do what I wrote

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

    (1-3)^2,(2-3)^2,(3-3)^2,(4-3)^2,(5-3)^3 4,1,0,1,4

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

    so 0,1,4

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

    that is the range (or support)

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

    now you can find the pmf

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

    right?

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

    so y=(x-3)^2 do we solve for x?

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

    no

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

    \[P_{Y}(0)=P_{X}(3)\] \[P_{Y}(1)=P_{X}(2)+P_{X}(4)\] \[P_{Y}(4)=P_{X}(1)+P_{X}(5)\]

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

    can you explain me how you got that?

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

    \[P_{Y}(1)=P(Y=1)=P(X=2\text{ or }X=4)\] \[=P(X=2)+P(X=4)=P_{X}(2)+P_{X}(4)\]

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

    ok?

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

    still figuring out the last post

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

    ok

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

    I understand you sum because it is 'or' but why is P(y=1) = P(x=2 or x=4)

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

    \[Y=(X-3)^2\] \[1=(2-3)^2\] \[1=(4-3)^2\] if I tell you Y=1 then either X=2 or X=4

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

    got it

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

    good

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

    so that's just P(Y=1) do we find Y=1,2,3,4,5?

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

    Y only takes the values 0,1,4

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

    got it , thanks; I wish you were my probability professor

  33. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.