Wes and Libbie each surveyed groups of students to find whether they would prefer going to an art museum or to the zoo. Wes found that 90% of the students he surveyed wanted to go
to the zoo. Libbie found that 60% of the students she surveyed wanted to go to the zoo. When
the teachers surveyed all the students, they found that 62% wanted to go to the zoo. Which of
these most likely explains why Wes's data were so different than the other two surveys?