Kelvin and Lewie each design surveys in order to determine the average number of people who buy food at the mall. Kelvin surveys every other person leaving the food area. Lewie surveys every fifth person leaving the mall’s main entrance.
Which set of survey results is most likely to show biased results for people who buy food at the mall?
Kelvin’s because he surveyed people leaving an area where food is sold
Kelvin’s because he surveyed every other person instead of every fifth person
Lewie’s because he surveyed every fifth person instead of every other person
Lewie’s because he surveyed people who may or may not have bought food
