Answer:
He has surveyed the students who are already participating in the choir. So naturally the number of students who likes the choir class will be higher than in other classes. You can see it reflected in the data.
Explanation:
He has surveyed the students who are already participating in the choir. So naturally the number of students who likes the choir class will be higher than in other classes. You can see it reflected in the data.
If he needs to make an inference on the whole school he needs to randomly pick people from the school and ask the same question. Then he can make a better inference about the favorite class of students.