document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=928500>Question 928500</A>: <I><SPAN STYLE=\"word-break: break-all;\"> According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase.  Random samples of size 50 are selected.<BR>\n" );
document.write( "What is the average of all the sample proportions of customers who will make a purchase after visiting the web site?<BR>\n" );
document.write( "What is the standard deviation of all the sample proportions of customers who will make a purchase after visiting the web site?<BR>\n" );
document.write( " What proportion of the samples will have between 20% and 30% of customers who will make a purchase after visiting the web site?<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 #563649 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=563649\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> According to a survey, only 15% of customers who visited the web site of a major retail store made a purchase. Random samples of size 50 are selected.<BR>\n" );
document.write( " What is the average of all the sample proportions of customers who will make a purchase after visiting the web site?<BR>\n" );
document.write( "Ans: 0.15<BR>\n" );
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document.write( " What is the standard deviation of all the sample proportions of customers who will make a purchase after visiting the web site?<BR>\n" );
document.write( "Ans; sqrt[0.15*0.85/50] = 0.05 <BR>\n" );
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document.write( " What proportion of the samples will have between 20% and 30% of customers who will make a purchase after visiting the web site?<BR>\n" );
document.write( "z(0.2) = (0.2-0.15)/0.05 = 0.05/0.05 = 1<BR>\n" );
document.write( "z(0.3) = (0.3-0.15)/0.05 = 0.15/0.05 = 3<BR>\n" );
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document.write( "P(0.2 < p < 0.3) = P(1< z < 3) = 0.157<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
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document.write( "</TD></TR></TABLE>\n" );