Flu Fiasco

Charlotte's town is drowning in flu cases. 10,000 people live there, and many struggle to get a doctor's appointment. The city estimates that 5% of the population is sick.

Charlotte has no symptoms, but she buys a test from the pharmacy, and the result returns positive! Reading the instructions, she discovers that the test is 90% accurate.

What do you think is Charlotte's probability of being healthy?

Charlotte is likely sick with a 90% probability.

Charlotte is likely healthy with a 68% probability.

Charlotte is likely sick with a 68% probability.

Charlotte is likely healthy with a 95% probability.