Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

AJACW22

  • one year ago

Suppose x is normally distributed random variable with μ = 12 and σ =2. Find each of the following probabilities. a. P (x ≥ 13.5) b. P (x ≤ 8) c. P (12.62 ≤ x ≤ 16.54) d. P (7.02 ≤ x ≤ 15.32)

  • This Question is Closed
  1. oldrin.bataku
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    They just want you to find Z-scores and look up the probabilities in tables. e.g. for the first, find the area to the right of \(Z\) where $$Z=\frac{13.5-12}2=\frac{1.5}2=0.75$$You can determine the area to the left and subtract from 1.

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

    (b) just wants the area to the left of \(Z=(8-12)/2=-4/2=-2\). Use your table. For (c) and (d), they want the area between two \(Z\):|dw:1370722148193:dw|

  3. AJACW22
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Oldrin, I don't have a solid background in Algebra or statistics. So i have problems working these problems out. I would not know how to get these anwers to c. and d. without a step by step.

  4. AJACW22
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    The answer they have for a and b are 0.227 and 0.023?

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

    Okay. For (c), first find the appropriate \(Z\) scores:$$Z_1=\frac{12.62-12}2=\frac{0.62}2=0.31\\Z_2=\frac{16.52-12}2=\frac{4.52}2=2.26$$We want the area between the two. Graphically, you can see this is the difference in their respective left-tails:|dw:1370722767214:dw|

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

    So find the areas to the left of \(Z=2.26\) and \(Z=0.31\) in your table. Find their difference.

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

    Search OpenStudy
    • 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.