document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1188219>Question 1188219</A>: <I><SPAN STYLE=\"word-break: break-all;\"> It is estimated that 0.42 percent of the callers to the Customer Service department of Dell Inc. will receive a busy signal. What is the probability that of today’s 1,200 callers at least 5 received a busy signal? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #819283 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=819283\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> This is a binomial<BR>\n" );
document.write( "look at 0,1,2,3,4 and subtract that sum from 1, and the answer will be at least 5.<BR>\n" );
document.write( "p(x=0)=9958^1200=0.0064<BR>\n" );
document.write( "p(x=1)=0.9958^1199*0.0042*1200=0.0324<BR>\n" );
document.write( "p(x=2)=1200C2*0.9958^1198^0.0042^2=0.0820<BR>\n" );
document.write( "p(x=3)=1200C3^0.9958^1197*0.0042^3=0.1381<BR>\n" );
document.write( "p(x=4)=1200C4*0.9958^1196*0.0042^4=0.1743<BR>\n" );
document.write( "sum=0.4332<BR>\n" );
document.write( "the answer is therefore 0.5668<BR>\n" );
document.write( "Can check on the calculator using 1-binomcdf(1200,0.0042,4) and get 0.5669. There is slight rounding error in the above calculation. <BR>\n" );
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