document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1023101>Question 1023101</A>: <I><SPAN STYLE=\"word-break: break-all;\"> the average of first three numbers is double from fourth no. if the average of all four number is 28 find out the fourth number </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #638627 by </B><A HREF=/tutors/aboutme.mpl?userid=god2012><B>god2012(113)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=god2012><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=god2012><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=638627\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let the numbers be a,b,c and d.<BR>\n" );
document.write( "Average of first 3 numbers is double the 4th<BR>\n" );
document.write( "(a+b+c)/3 = 2d => (a+b+c) = 6d -----------eq.1\r<BR>\n" );
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document.write( "Avg. of all 4 numbers is\r<BR>\n" );
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document.write( "(a+b+c+d)/4 = 28 => /(a+b+c+d) = 28*4 = 112 ----eq.2<BR>\n" );
document.write( "Put eq.1 in eq.2\r<BR>\n" );
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document.write( "6d + d = 112<BR>\n" );
document.write( "7d = 112<BR>\n" );
document.write( "d = 112/7\r<BR>\n" );
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document.write( "d = 16<BR>\n" );
document.write( "So, the 4th number is 16 </SPAN>\n" );
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