I did say the answer is $35. Because, you should use the highest factor or whatever operation the problem is using, to find the answer. Not sure if it's some two-step problem....
Add them up and you have your answer
Answer:
0.0713 = 7.13% probability that the result is positive.
Step-by-step explanation:
Probability of a positive test:
91% of 1/650(has the disease).
7% of 1 - 1/650 = 649/650(does not have the disease). So

0.0713 = 7.13% probability that the result is positive.