document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1100467>Question 1100467</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3. A telephone poll of 800 American adults asked \"where would you rather go in your spare time?\"  One response, by 275 adults, was \"a movie\". Compute and explain a 90% confidence interval estimate of the proportion of all American adults who would respond \"a movie\". </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #715048 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=715048\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 90% CI half interval is 1.645*sqrt(0.34375*0.65625)/800; 0.34375 is 275/800.<BR>\n" );
document.write( "=1.645*0.0168<BR>\n" );
document.write( "0.0276<BR>\n" );
document.write( "the mean is 0.34375<BR>\n" );
document.write( "The CI is the mean +/- the half interval<BR>\n" );
document.write( "(0.316, 0.371)We are 90% confident that the true proportion, which we don't know and never will lies in this interval.  All values in this interval are plausible.<BR>\n" );
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