A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

A test for a virus correctly identifies someone who has the virus (by returning a positive result) 99% of the time. The overall population is 1,000,000 people. The test correctly identifies someone who does not have the virus (by returning a negative result) 99% of the time. It is known that 0.5% of the population has the virus. A doctor decides to treat anyone who tests positive for the virus. Is this a good decision?

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

    |dw:1437356833995:dw|

  2. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    `It is known that 0.5% of the population has the virus` `The overall population is 1,000,000 people` how many people have the virus?

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

    500,000?

  4. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    0.5% = 0.005 multiply 0.005 by 1 million

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

    5000

  6. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    yep so 995,000 don't have the virus

  7. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    |dw:1437357954036:dw|

  8. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    `A test for a virus correctly identifies someone who has the virus (by returning a positive result) 99% of the time` so if you have the virus, then there is a 99% chance that the test gets it right that means 0.99*5000 = 4,950 people will get tested positive (the ones who have the virus) |dw:1437358056159:dw|

  9. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    1% will test negative 0.01*5000 = 50 |dw:1437358100248:dw|

  10. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    `The test correctly identifies someone who does not have the virus (by returning a negative result) 99% of the time` 99% of (total who don't have virus) = 0.99*995,000 = 985,050 |dw:1437358184431:dw|

  11. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    what goes in the box with the question mark |dw:1437358210567:dw|

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

    9950 people

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

    I can take it from here thanks!

  14. jim_thompson5910
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    no problem

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

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

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.