A utility company hires pollsters to knock on random doors in different parts of town to survey residents about the cost of their electric bill. Would this study be biased? Why or why not?
Answer
A
Yes, it is biased. Only certain parts of the town were surveyed.
B
Yes, it is biased. Some of the residents who are surveyed may not want to respond to someone who knocks at their door.
C
No, it is not biased. All residents who are surveyed will want to respond.
D
No, it is not biased. All residents of the town will have the opportunity to respond.