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 best explains which student's survey is likely to produce less valid results?

A. Kelvin's because he surveyed people leaving an area where food is sold

B. Kelvin's because he surveyed every other person instead of every fifth person

C. Lewie's because he surveyed every fifth person instead of every other person

D. Lewie's because he surveyed people who may or may not have bought food

A. Kelvin's because he surveyed people leaving an area where food is sold

Step-by-step explanation:

Since, the goal is to determine the average number of people who bought food, the mistake in Kelvin's strategy is that his method excluded all the other people who are not entering in the food area.

According to probability theory, there is a strong likely hood that people who entered the food area will buy food, so surveying them will never reflect the average number of mall visitors who buy food in court area.

Remember that the fault is not about surveying every second or fifth person, but about surveying a small number of whole visitors who come to the mall.

D. Lewie's because he surveyed people who may or may not have bought food

Step-by-step explanation:

The essence of the survey is to determine the average number of people who buy food at the mall.

Lewie surveyed every fifth person and not people who went to the buy food, but the people leaving the mall's main entrance which is a very wrong approach to the essence of the survey.

However, Kevin surveys every other person leaving the food area.