1. The ELISA HIV Blood Test Application example for probabilities ELISA is a test for AIDS used to screen donated blood for hiv. (See http://www.stat.ucla.edu/cases/elisa/ )http://www.stat.ucla.edu/cases/elisa/

2. Here's a simplified scenario for 1,010,000 people donating blood and the results on their blood:

3. Randomly pick one person from these 1,001,000. Fill in the blanks below: 1.The chance the person has AIDS is____________________ 2.The chance the person tests positive given the person has AIDS is _________ 3.The chance the person tests positive given the person does not have AIDS is_____ 4.Are "having AIDS" and "testing Positive" independent? _______ _______________________________________________ 5.The chance the person has AIDS given the person does not test positive is__________ 6.The chance the person has AIDS given the person tests positive is____________ 7. Testing positive means: 5.The person almost certainly has AIDS 6.The person probably had AIDS 7.The person has a fifty-fifty chance of having AIDS 8.The person probably doesn't have AIDS, but may 9.The person definitely does not have AIDS.

4. Answers: