document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=478988>Question 478988</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Smallville Bank has 650 checking accounts.  A recent sample of 50 of these customers showed 26 have a Visa card with the bank.  Construct a 99% or .99 confidence interval for the proportion of checking account customers who have a Visa account with the bank.<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #328212 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=328212\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Smallville Bank has 650 checking accounts. A recent sample of 50 of these customers showed 26 have a Visa card with the bank. Construct a 99% or .99 confidence interval for the proportion of checking account customers who have a Visa account with the bank.\r<BR>\n" );
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document.write( "sample proportion: 26/50 = 0.13<BR>\n" );
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document.write( "ME = 2.5758*sqrt[0.13*0.87/650] = 0.034<BR>\n" );
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document.write( "99% CI: 0.13-0.034 < p < 0.13+0.034<BR>\n" );
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document.write( "0.096 < p < 0.164<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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