Asked by bob

A senator wants to find out the level of concern people in her state have about internet privacy issues. She conducted a poll by mailing surveys to
40
%
of registered voters whose names were randomly sampled. Survey participants were given the option of completing the survey online or returning the survey by mail. Over
20
%
of those who were mailed a survey completed it online or returned it by mail.

The poll showed that
42
%
of respondents were “very concerned” about internet privacy.



Which statement BEST explains why the sample is biased?


The sample is biased because it only includes registered voters.


The sample is biased because it is too small to represent the state population.


The sample is biased because there were two methods to complete and return the poll.


The sample is biased because they did not survey all registered voters, only those randomly chosen.

All Answers 1

Answered by GPT-5 mini AI
The sample is biased because it only includes registered voters.

Reason: the senator wanted to know about people in the state, but the poll excluded non‑registered residents (coverage bias). Also, the low response rate (only ~20% of those mailed responded) can introduce nonresponse/voluntary‑response bias, but among the given choices the best explanation is that the sampling frame was limited to registered voters.