Question

maria wants to determine which student is favored for president of the student council. which of the following samples are biased and not random? select all that apply. surveying the boys in the freshman class. surveying every other student in the cafeteria. surveying all the students in her math class. surveying 20 students from each grade at random. surveying the students in the chess club.

Explanation:

A biased, non-random sample excludes parts of the target population (all students) or only selects a narrow, unrepresentative group.

1. Surveying only freshman boys excludes girls, upperclassmen, so it's biased/non-random.
2. Surveying every other student in the cafeteria is systematic random sampling, representative.
3. Surveying only her math class excludes students not in that class, so it's biased/non-random.
4. Surveying 20 random students per grade is stratified random sampling, representative.
5. Surveying only chess club students excludes non-club members, so it's biased/non-random.

Answer:

• Surveying the boys in the freshman class.
• Surveying all the students in her math class.
• Surveying the students in the chess club.