In a study, Researcher A took a random sample of 25 college students and found the mean number of times they went out to eat during the last week was 4.1. In another study, Researcher B took a random sample of 25 students from the same college and found the mean number of times they went out to eat during the last week was 3.7. What is the best explanation for why the samples taken by Researcher A and Researcher B did not produce the same mean