Question

Which of the following explains what a researcher could do to increase chances of selecting a representative sample for a survey to evaluate customer satisfaction of people who use a certain cell phone service?
A. Survey all of the customers who recently purchased a new cell phone plan.
B. Survey randomly selected customers who terminated their cell phone contract early.
C. Survey all of the customers who use the cell phone service in one city selected at random.
D. Survey randomly selected customers from the list of all of the cell phone service customers.

Answer 1

C. Survey all of the customers who use the cell phone service in one city selected at random.
A sample survey normally provides larger scope than a census. 
It is critical that researchers accepts the population on a case-by-case basis and test the sample for consistency before moving ahead with the survey.