Quick simple probablity question (1 Viewer)

[JMFH]

heyy guys!
im so retarded hey haha i cant figure out this one

Based on medical results, if apositive test is recorded what is the probabliity that you actually have the virus?
-------------------accurate -----not accurate----total
with virus:---------45----------------3-------------48
without virus-----922---------------30-----------952
Total:--------------967---------------33----------1000

would be much help asap coz im killing myself here haha thanks in advance!!!
maths isnt my thing ide like to not bottom the class!
jess

 

[insert-username]

Out of 967 tests that recorded positive, 922 were actually correct. So the probability is 922/967, or about 95.4%.


I_F

 

[JMFH]

hey thanks for the help,

i figured it out im pretty sure

after studying the theory of p more i guessed that it means somehow.

P(have the virus)= accurate tests with the virus / (accurate with virus + not accurate without virus)

this meant that all that had been infected were inclusive of non infected test subjects, which explains its error, thus 45/75 = 3/5... and back of book corresponds correctly.

im pretty sure thats exactly how..
thanks I_F, you read the question how i did originally (at one of the many points actually haha) but what it included was the subjects that didnt have infections. Which is not correspondent to the question. The question to your answer would be, i assume, What is the probability of not having the virus based on an accurate only result.

If im way off and am as stupid as i think at maths please tell me as bluntly as possible!

Thankss guys!!! jess