document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1171108>Question 1171108</A>: <I><SPAN STYLE=\"word-break: break-all;\"> According to a survey only 20% of customers who visited tje website of a major retail store made a purchase. random sample sizes of 75 are selected.\r<BR>\n" );
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document.write( "What proportion of the sample will have between 10% and 40% of customers who will make a purchase after visiting the website </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #796052 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=796052\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the mean is np=75*0.20=15<BR>\n" );
document.write( "the variance is np(1-p)=15*0.8=12<BR>\n" );
document.write( "the sd is sqrt(V)=3.464<BR>\n" );
document.write( "10% is 7.5 customers (we would consider 8 the bottom number)<BR>\n" );
document.write( "40% is 30 customers<BR>\n" );
document.write( "with the continuity correction factor, we would use 7.5  and 30.5 for the two values.<BR>\n" );
document.write( "z=(7.5-15)/3.464 with z of -2.165<BR>\n" );
document.write( "for 30.5<BR>\n" );
document.write( "z=(30.5-15)/3.464<BR>\n" );
document.write( "=+4.47<BR>\n" );
document.write( "the probability of z's being in between those values is 98.5% </SPAN>\n" );
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