PSAT Math Multiple-Choice Question 740: Answer and Explanation

Question: 740

The survey summary states that the researcher collected the data "randomly." Which of these methods of finding survey participants would likely provide the most accurate results given the researcher's goal?

• A. Ask for volunteer responses through television advertising and give a number for interested subjects to call in, ensuring a high level of motivation among survey participants
• B. Have a survey booth at a local shopping mall where only every 5th person is selected to share his or her individual thoughts about social media use, ensuring that each participant provides photo ID to verify his or her identity
• C. Post a survey advertisement on a variety of websites that appeal to a great number of demographic groupings, including income, gender, and ethnicity
• D. Call randomly selected phone numbers from across the country, both cellular and landlines, and ask for household members of a particular random age group to share their thoughts

Correct Answer: D

Explanation:

(D) Calling people from as large a group as possible from as many phone types and age groups as possible will ensure that the results are highly accurate. The other choices limit the samples to groups who do particular types of activities. The other choices would give results accurate for that sample but not for the population as a whole.