Gun Control On Oct. 29, 2015, The Grand Rapids Press ran a story titled, "Support for gun limits increases, latest poll shows"[75]. At the end of the story was a description of the sampling method used to select survey participants. Quoting from the article, The AP-GfK poll of 1,027 adults was conducted Oct. 15 to Oct. 19 online, using a sample drawn from GfK's probability-based KnowledgePanel, which is designed to be representative of the U.S. population. The margin of sampling error for all respondents is plus or minus 3.3 percentage points. Respondents were first selected randomly using telephone or mail survey methods, and later interviewed online. People selected for KnowledgePanel who didn't otherwise have access to the Internet were provided access at no cost to them. (a) Who conducted the poll? (b) What is the sample size for the survey? (c) What is meant by "designed to be representative of the U.S. population?" (d) What is meant by the phrase "Respondents were first selected randomly