A marketing research firm, in conducting a comparative taste test, provided three types of peanut butter to a sample of households randomly selected within the state. Which of the four methods of data collection is involved when people are asked to compare the three types of peanut butter?
举一反三
- Which of the four methods of data collection is involved when a person retrieves data from an online database?
- If I eat peanut butter, I ________ sick.
- The British Airways Internet site provides a questionnaire instrument that can be answered electronically. Which of the four methods of data collection is involved when people complete the questionnaire?
- What are the three types of benefits provided by Social Security?
- According to transformer insulation and cooling methods, there are three types: 、 、 。