Tuesday HW

Good work today! Tomorrow we'll continue to work with some conditional probability...we'll look at the insurance example (on the back of the paper we started today) and then you'll have some practice on your own!

Tonight, please complete questions a-g on the worksheet we started in class. Here is the worksheet (in case you were out or lost yours):

Homework Questions:

Example 2: HIV Testing

The OraQuick In-Home HIV Test: Oral fluid HIV tests are very accurate. In studies, the OraQuick oral fluid test detected 91.7 percent of people who were infected with HIV, and 99.9 percent of people who were not infected with HIV.
The prevalence of HIV is estimated to be about 0.5% in the general population.Oral fluid HIV tests are very accurate. In studies, the OraQuick oral fluid test detected 91.7 percent of people who were infected with HIV, and 99.9 percent of people who were not infected with HIV.If you have more questions about oral fluid HIV tests, talk to your doctor or healthcare provider. He or she can help you figure out the best test for you.Oral fluid HIV tests are very accurate. In studies, the OraQuick oral fluid test detected 91.7 percent of people who were infected with HIV, and 99.9 percent of people who were not infected with HIV.

If you have more questions about oral fluid HIV tests, talk to your doctor or healthcare provider. He or she can help you figure out the best testa.)   Create a tree-diagram to model the scenario above.

b.)   What is the probability that an individual has HIV and tests negative?
c.)   What is the probability that an individual does not have HIV and tests positive?
d.)   What percent of people who take the OraQuick test will test positive for HIV?
e.)   What is the probability that someone has HIV if we know they tested positive using the Oraquick test?
f.)    What is the probability that someone who tested positive with the Oraquick test actually does not have HIV?
g.)   What is the probability that someone who tested negative actually does have HIV?