document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1196345>Question 1196345</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A supermarket wants to estimate the percentage of shoppers paying cash for their purchases. On a particular day 526 of the 950 shoppers who made purchases at the supermarket paid in cash. Calculate a 90% confidence interval for the percentage of shoppers paying cash for their purchases.      </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #829141 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=829141\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 90% half-interval is z(0.95)*sqrt(p91-p)/n)<BR>\n" );
document.write( "p=526/950=0.554<BR>\n" );
document.write( "so half-interval=1.645*sqrt(0.554*0.456)/950)<BR>\n" );
document.write( "=0.027<BR>\n" );
document.write( "the interval is 0.554+/-0.027 or (0.527, 0.581) </SPAN>\n" );
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