In a poll taken in December 2012, Gallup asked 1006 national adults whether they were baseball fans;
48.2%
said they were. Almost five years earlier, in February 2008 , only
34.6%
of a similar-size sample had reported being baseball fans. Complete parts a through e below. a) Find the margin of error for the 2012 poll if we want
90%
confidence in our estimate of the percent of U.S. adults who are baseball fans. ME
=
(Round to three decimal places as needed.) b) Explain what that margin of error means. A. One is
90%+-
ME confident that the true proportion of adults who are baseball fans is equal to this poll's estimate. B. In
90%
of samples of adults, the proportion who are baseball fans will be within
+-ME
of this poll's estimate. C. There is a
90%
chance that the true proportion of adults who are baseball fans is within
+-
ME of this poll's estimate. D. One is
90%
confident that this poll's estimate is within
+-
ME of the true proportion of adults who are baseball fans In a poll taken in December 2012, Gallup asked 1006 national adults whether they were baseball fans;
48.2%
said they were. Almost five years earlier, in February 2008 , only
34.6%
of a similar-size sample had reported being baseball fans. Complete parts a through e below. c) If we wanted to be
99%
confident, would the margin of error be larger or smaller? Explain. A. To be more confident, the intervals need to contain the true proportion less often, so the margin of error would be smaller. B. To be more confident, the intervals need to contain the true proportion more often, so the margin of error would be smaller. C. To be more confident, the intervals need to contain the true proportion less often, so the margin of error would be larger. D. To be more confident, the intervals need to contain the true proportion more often, so the margin of error would be larger. d) Find that margin of error.
ME=
(Round to three decimal places as needed.) e) In general, if all other aspects of the situation remain the same, will smaller margins of error produce greater or less confidence in the interval? Greater confidence Less confidence