Avra, Evan, and Tam were working on a survey. They each polled people over the weekend to determine if the subject of a large new mural downtown should be wildlife, sports, or black history. Avra forgot about her homework until the last minute, so she quickly surveyed her family and any relatives she could reach on the phone. Evan talked to some of the people in the stands at his baseball game Saturday, and Tam questioned people leaving a local church. Each got very different results. Explain why.