Coscott comments on Open thread, July 21-27, 2014 - Less Wrong
You are viewing a comment permalink. View the original post to see all comments and the full post content.
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (160)
Are we assuming the two tests are independent?
If so, the original cancer rate was 5:95. Multiply that by 80:9 for the likelihood ratio of getting a positive to get 400:855, which is ~30% as you said. Then, you multiply by the likelihood ratio of getting the second negative 20:91, to get 8000:77805, which as a probability is 8000/(8000+77805)~9.3%.