Question

Jordan wants to estimate the number of students in his school who have their own cell phone. He surveys every eighth person who enters the cafeteria for lunch. Is this sample biased or unbiased. Explain.

Answer 1

Explanation:

I wouldn't consider it biased, but I'll bet a stats person would. Their reason would be that those who enter the cafeteria are select segment of a school population.

• What about the kids who go to clubs at noon? or other activities.
• What about those who are only there part time and have jobs or just go home at noon?
• What about those who bring lunches and want to sit outside or even in their cars if they have one?
• What about those who are serving detentions?

Those are just four exceptions. There must be others -- like a staggered lunch period.