Rashad and Kendra were walking through the park and noticed several hummingbirds on a tree with yellow flowers. They wanted to know if the color yellow attracts hummingbirds more than other colors. Rashad and Kendra 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, Rashad and Kendra 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 Rashad and Kendra reach?