Pat and Terry believe the color yellow attracts hummingbirds. They decided to test their hypothesis by doing an experiment in which they set up four hummingbird feeders with the same amount of food and placed them in locations only hummingbirds could reach. One feeder was yellow, one was red, one was blue, and one was clear. Each day for one week, Pat and Terry measured and recorded the amount of food left in each of the feeders. At the end of the experiment the red feeder had the least amount of food left in it. What conclusion should Pat and Terry reach?