document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=971925>Question 971925</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The costs of a trucking company vary jointly as the number of trucks in service and the number of hours they are used. When 4 trucks are used for 5 hours each, the costs are $1500. Find the costs of using 10 trucks, each for 11 hours. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #594343 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=594343\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> joint variability<BR>\n" );
document.write( "4 trucks*5 hours cost $1500.  It is 20 truck-hrs. or $75 (1500/20) per truck-hr.\r<BR>\n" );
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document.write( "10 trucks *11 hours is 110 truck-hrs.  The cost would be $75 * 110=$8250.\r<BR>\n" );
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document.write( "It is 2.5 times the number of trucks and 2.2 times the number of hours.<BR>\n" );
document.write( "Joint variability is multiplying by both, which is here 2.5*2.2=5.5 \r<BR>\n" );
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document.write( "$1500*5.5=$8250. </SPAN>\n" );
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