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3STATS applied! Does hand sanitizer work? While traveling, going to restaurants, shopping in grocery stores, and visiting public spaces, many people use hand sanitizer to try to avoid getting sick. But is soap better than hand sanitizer for getting rid of unwanted bacteria? Researchers designed an experiment to find out. Using 30 identical petri dishes, they randomly assigned 10 students to press one hand in a dish after washing with soap, 10 students to press one hand in a dish after using hand sanitizer, and 10 students to press one hand in a dish after using nothing. After three days of incubation, they counted the number of bacteria colonies on each petri dish. 1 Which petri dishes had the most bacteria colonies? What conclusion did the researchers make based on the data? We%u2019ll revisit STATS applied! at the end of the chapter, so you can use what you have learned to help answer these questions. Wysiati/iStock/Getty Images%u00a9 Bedford, Freeman & Worth Publishers. For review purposes only. Do not distribute.