Question

A certain disease has an incidence rate of 0.5%. If the false negative rate is 4% and the false positive rate is 2%, compute the probability that a person who tests positive actually has the disease.

Answer 1

start by drawing probability tree

Answer 2

If the false negative rate is 4%

that means, eventhough disease is present, the test shows NEGATIVE falsely

Answer 3

false positive rate is 2%

wat does that mean ?

Answer 4

"false positive" means, the disease is not there, but the test shows POSITIVE

Answer 5

see if the probability tree makes sense

Answer 6

you need to find :

P(diseased | positive)

Answer 7

How would I compute P(diseased | positivie)?

Answer 8

*positive

Answer 9

heard of bayees theorem ?

Answer 10

P(diseased | positive) = P(diseased AND positive) / P(positive)

Answer 11

find both of them, and plugin

Answer 12

Okay thank you!

Answer 13

np :) wat do u get ?