document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1100387>Question 1100387</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A business firm has a 24-hour toll-free telephone hotline. Calls arrive at the rate of three per hour.\r<BR>\n" );
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document.write( "(Enter your answers as fractions in simplest form or as decimals rounded to four decimal places.)\r<BR>\n" );
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document.write( "a. What is the average number of calls received on a certain 7-hour interval?\r<BR>\n" );
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document.write( "b. What is the probability that at most five calls will be received on a certain 4-hour interval? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #714902 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=714902\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Average number of calls will be 21, the 3 per hour * 7 hours<BR>\n" );
document.write( "In 4 hours, expect 12 calls.<BR>\n" );
document.write( "Poisson has parameter 12<BR>\n" );
document.write( "e^(-12)*12^5/5!=0.0127<BR>\n" );
document.write( "e^(-12)*12^4/4!=0.0053<BR>\n" );
document.write( "e^(-12)*12^3/6=0.0018<BR>\n" );
document.write( "e^(-12)*144/2=0.0004<BR>\n" );
document.write( "e^(-12)*12=0.00007<BR>\n" );
document.write( "rounding the last the sum is 0.0203. </SPAN>\n" );
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