CompTIA Data+ (DA0-001) — Question 34

A county in Illinois is conducting a survey to determine the mean annual income per household. The county is 427sq mi (2.65q km). Which of the following sampling methods would MOST likely result in a representative sample?

Answer options

• A. A stratified phone survey of 100 people that is conducted between 2:00 p.m. and 3:00 p.m.
• B. A systematic survey that is sent to 100 single-family homes in the county
• C. Surveys sent to ten randomly selected homes within 5mi (8km) of the county’s office
• D. Surveys sent to 100 randomly selected homes that are reflective of the population

Correct answer: D

Explanation

The correct answer is D because sending surveys to 100 randomly selected homes that reflect the population ensures that various demographics and characteristics are included, providing a comprehensive view of the county's income. The other options either limit the sample size, focus on a specific time, or are geographically restricted, which may not accurately capture the overall income distribution.