There was a dramatic increase in the asthma rate in the 1980s and 1990s. In 2016, the Centers for Disease Control and Prevention (CDC) reported that about 8% of children in the U. S. had been diagnosed with asthma. Researchers have been working to understand this phenomenon. Asthma is a complicated illness. Unlike HIV or the common cold, it is not transmitted from person to person. Rather, doctors think a combination of genetic factors and environmental factors, like pollution, determine who gets asthma. Asthma attacks can be life-threatening, and treating asthma is expensive. For these reasons, some say fighting asthma should be a national priority. But how can we fight asthma? Realistically, we cannot suspend all activities that cause pollution. To plan e!ective interventions, we need to know which groups are most a!ected. Here are some more statistics from the CDC’s 2016 report: • 9.2% of boys had been diagnosed with asthma, as compared to 7.4% of girls • 11.4% of children living in poverty had been diagnosed with asthma, as compared to 7.1% of children in the highest income category (at least 4.5 times the national poverty level) question: Two boys are chosen at random. According to the statistics given above, what is the likelihood that they both have asthma?