Two random samples were done to determine how often people in a community go to the dentist the first sample surveyed 10 people as they enter their workplaces. The first sample found that the mean time between visits to the dentist with 7.5 months. The second sample survey 50 people as they enter the local grocery store. The second simple found that the mean time between visits to the dentist is 18.1 months. Which statements are true check all that apply