A research firm was hired to conduct a survey on smartphone usage among adults in a major metropolitan area. The firm conducted telephone interviews by calling randomly selected landline numbers between 9:00 AM and 5:00 PM on weekdays. The survey reported that 75% of respondents primarily use their smartphone for making calls. Which of the following best explains why these results might not accurately reflect the smartphone usage habits of all adults in the metropolitan area?
The survey should have been conducted over a longer period of time.
Many adults do not have landline phones or are at work during the survey hours.
The survey did not ask about other types of smartphone usage, such as texting or internet browsing.
People are often reluctant to answer calls from unknown numbers.
