Not all telephone polls carried out to estimate voter or consumer preferences make calls to cell phones. One reason is that in the United States, automated calls (“robocalls”) to cell phones are not permitted and interviews conducted by humans are more costly.

a. How might the strategy of leaving out cell phones affect the goal of obtaining a random sample of voters or consumers?

b. Which criterion of random sampling is most likely to be violated by the problems you identified in part (a): equal chance of being selected or the independence of the selection of individuals?

c. Which attribute of estimated consumer preference is most affected by the problem you identified in (a): accuracy or precision?