The residents of an apartment complex are considering the filing of a lawsuit against a chemical factory that opened up a few blocks down the street from them. They claim that the factory is releasing unhealthy levels of sulfur dioxide into the air and that it is impacting their health. You have been called in to take air samples from various residents’ apartments to determine an average air quality rating. A diagram of the apartment complex and factory are shown. Devise a sampling method to take a size 60 sample of the air for levels of sulfur dioxide. Your sample should be designed to be as unbiased as possible, and you should also aim to reduce variability. Each building contains 29 apartment residences.