Suppose that an epidemiologist is asked to investigate the possible hazard from an inadequate air filtration system in a large school building in a poor urban neighborhood. The particular concern involves children with asthma, 400 of whom attend the school (school A). The epidemiologist is informed that on a particular day, 12 children suffered an asthmatic attack, whereas at a very similar nearby school (school B) with 500 asthmatic children, only 5 suffered an asthmatic attack on the same day. Estimate and interpret the risk ratio.