document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=616203>Question 616203</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3. Your firm’s accountant believes that 15% of the company’s invoices contain arithmetic errors. To check this theory, the accountant randomly selects 50 and checks them.<BR>\n" );
document.write( " <BR>\n" );
document.write( "a) Give the formula for the probability that exactly six of them are in error.<BR>\n" );
document.write( "b) Give the mean and standard deviation for distribution representing the number of invoices among the 50 that are in error.<BR>\n" );
document.write( "c) Which is larger: the mean or the median? Why?<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #387613 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=387613\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Your firm’s accountant believes that 15% of the company’s invoices contain arithmetic errors. To check this theory, the accountant randomly selects 50 and checks them.<BR>\n" );
document.write( " <BR>\n" );
document.write( "a) Give the formula for the probability that exactly six of them are in error<BR>\n" );
document.write( "P(x = 6) = 50C6*(0.15)^6*(0.85)^45<BR>\n" );
document.write( "------------------------------------------------<BR>\n" );
document.write( "b) Give the mean and standard deviation for distribution representing the number of invoices among the 50 that are in error.<BR>\n" );
document.write( "mean = np = 50*0.15 = 7.5<BR>\n" );
document.write( "std = sqrt(npq) = sqrt(7.5*9.85) = 2.5249<BR>\n" );
document.write( "------<BR>\n" );
document.write( "c) Which is larger: the mean or the median? Why?<BR>\n" );
document.write( "median = middle score of 0 to 15::: (7+8)/2 = 7.5<BR>\n" );
document.write( "mean = np = 7.5<BR>\n" );
document.write( "----<BR>\n" );
document.write( "The mean = the median<BR>\n" );
document.write( "=========================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );