Suppose a county’s recent health report gives a pet allergy prevalence of 0.15 for kids. There is a new at-home test kit for pet allergies on the market that provides families with a convenient way to test if children have a pet allergy. The probability that the test gives a positive result when a child really does not have a pet allergy is 0.07. The probability that the test gives a negative result when a child really does have a pet allergy is 0.22. The tree diagram shows the possible outcomes with the associated probabilities.