Question

Based on the tree diagram below what is the probability that the test for lice returns a false positive

Answer 1

Answer:

0.0492

Step-by-step explanation:

Based on the tree diagram we need to tell the the probability that the test for lice returns a false positive. False positive means that the student has no lice but still the test shows a positive result.

So for this we have to first look for the branch, from the starting node, which shows that student has no lice. From the starting point, the upper branch represents the students that have lice and lower branch represents the students who have no lice. So, we will consider the lower branch with probability mentioned as 0.82

Now, the lower branch is divided into two branches further. We have to look for the branch which shows positive test result. This would be the upper branch with probability mentioned as 0.06.

The overall probability of this event is mentioned at the end of the branch which is 0.0492

This is the probability of the combined event: Student has no lice but tests shows positive result which is the False positive.

Thus, the probability that the test for lice returns a false positive is 0.0492