document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=273271>Question 273271</A>: <I><SPAN STYLE=\"word-break: break-all;\"> An industrial firm allows a discount on any invoice that is paid within 30 days. it is known that 12% of all invoices recieve the discount. In a company audit 9 invoices are randomlu selected independent of each other. Let x be the number of invoices among the selected 9 that receive the discount.<BR>\n" );
document.write( "a- find the probability that exactly 3 invoices amond these 9 receive the discount.<BR>\n" );
document.write( "b- find the probability that at least one of the invoices receives a discount.<BR>\n" );
document.write( "c- find the mean and standard deviation of x. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #199650 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=199650\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> An industrial firm allows a discount on any invoice that is paid within 30 days.<BR>\n" );
document.write( "It is known that 12% of all invoices receive the discount. In a company audit 9 invoices are randomly selected independent of each other.<BR>\n" );
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document.write( "Binomial Problem with p = 0.12<BR>\n" );
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document.write( " <BR>\n" );
document.write( "Let x be the number of invoices among the selected 9 that receive the discount.<BR>\n" );
document.write( "a- find the probability that exactly 3 invoices among these 9 receive the discount.<BR>\n" );
document.write( "P(x=3) = 9C3(0.12)^3(0.88)^6 = 0.0674<BR>\n" );
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document.write( "b- find the probability that at least one of the invoices receives a discount.<BR>\n" );
document.write( "P(at least one) = 1 - P(none receive a discount<BR>\n" );
document.write( "P(at least one) = 1 - (0.88)^8<BR>\n" );
document.write( "= 1 - 0.3165<BR>\n" );
document.write( "= 0.6835<BR>\n" );
document.write( "===================<BR>\n" );
document.write( "c- find the mean and standard deviation of x.<BR>\n" );
document.write( "mean = np = 9*0.12 =1.08<BR>\n" );
document.write( "std = sqrt(npq) = 0.97488,,<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. <BR>\n" );
document.write( " </SPAN>\n" );
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