What potential sources of error might be associated with the following situations?

b. A telephone survey of big city voters finds that most respondents do not like negative political ads—that is, advertising by one political candidate that criticizes or exposes secrets about the opponent’s “dirty laundry.” Researchers conclude that negative advertising should not be used.

c. A survey accessed through Instagram produces results ranking Apple Macbooks as far superior to other PCs for business applications. A retailer decides to reduce inventory of PCs other than Macbooks.

d. Researchers who must conduct a 45-minute personal interview offer $175 to each respondent because they believe that people who will sell their opinions are more typical than someone who will talk to a stranger for free for 45 minutes. Management uses the results to adjust their services offering.

e. A company’s sales representatives are asked what percentage of the time they spend traveling, talking on the telephone, participating in meetings, working on the computer, in training, and filling out reports for management. The survey is conducted via the company’s email network. Management concludes that sales reps are not spending enough time performing selling in the field.