As an epidemiologist, Dr. Thompson is interested in determining the frequency with which a specified event occurs within a particular population at a certain instant or during a particular period. This measure is known as a rate. In epidemiologic practice, an attack rate is the most commonly used method of determining the extent or frequency with which a disease is experienced by a population of individuals. In this instance, Dr. Thompson is interested in knowing what percentage of the individuals who attended the July 4 celebration became ill. The attack rate is the number of individuals treated and/or had symptoms divided by the number of attending individuals. What is the attack rate of food poisoning among the group who attended the July 4 celebration?