document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1076606>Question 1076606</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me solve the probability question.\r<BR>\n" );
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document.write( "The record of a department store show that 10% of their customers who make a purchase return the merchandise in order to exchange it. What is the probability that in the next eight purchases three customers return the merchandise for exchange. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #691237 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=691237\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> binomial<BR>\n" );
document.write( "8C3(.1)^3*.9^5<BR>\n" );
document.write( "There are 8C3=56 ways three may be chosen, and the probabilities add to 1 and the exponents to 8<BR>\n" );
document.write( "0.0330<BR>\n" );
document.write( "This is low, does it make sense?<BR>\n" );
document.write( "The expected value is about 1 (0.8 to be exact), and the sd is about 0.85, so this is a reasonable answer. </SPAN>\n" );
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