document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1203200>Question 1203200</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I have another question about proportion.\r<BR>\n" );
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document.write( "THE TEXTBOOK GIVES THE FOLLOWING QUESTION under the heading ‘variation as the sum of two parts’; I cannot change the wording.\r<BR>\n" );
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document.write( "‘For a certain series of experiments it is known that a quantity F is directly proportional to H and the square root of P and inversely proportional to the square of D.<BR>\n" );
document.write( "If D = 8, H=40 and P=1000 when F=12, calculate the value of P when <BR>\n" );
document.write( "F = 8, d = 10 and H=30’.\r<BR>\n" );
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document.write( "The problem I seem to be having here is how to set up the equation.  The book is very vague about the difference between joint variation (which I have no problem with) and variation as the sum of two parts, but I am assuming, following the example in the book, that sum means add.\r<BR>\n" );
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document.write( "The notation that I am using here is the notation in the book.  If anyone finds it bizarre, there is nothing I can do about that.\r<BR>\n" );
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document.write( "I assume then that the equation could be stated thus: obviously I am using “Word” so I have included notes so that people are not in any doubt about the meanings.\r<BR>\n" );
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document.write( "F∝H  -  F is directly proportional to H;<BR>\n" );
document.write( "F∝√P  -  F is directly proportional to the square root of P;<BR>\n" );
document.write( "F∝1/D2  -  F is indirectly proportional to the square of D.<BR>\n" );
document.write( "I re  -  wrote this thus:<BR>\n" );
document.write( "F = kH;<BR>\n" );
document.write( "F = k√P;<BR>\n" );
document.write( "F = k(1/D2)<BR>\n" );
document.write( "WHERE K STANDS FOR THE CONSTANT OF PROPORTIONALITY.\r<BR>\n" );
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document.write( "I then combined the terms thus:\r<BR>\n" );
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document.write( "F=k(H*√P)+(1/D2)\r<BR>\n" );
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document.write( "I have added 1/D2 because the title of this section of the book that I am using is the sum of two parts, so I am assuming that 1/D2 is the second part and, thus, should be added.  \r<BR>\n" );
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document.write( "I cannot get the correct answer to the question even if I multiply all of the terms and I cannot see where I am going wrong.  I have tried to find information about “Variation as the sum of two parts” on the internet, and “Bing”, Google” and “You Tube” cannot understand the difference between the words variation and variance, which does not surprise me in the least, so no help there.  The solution is probably very simple, but I just cannot see it<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #838567 by </B><A HREF=/tutors/aboutme.mpl?userid=ikleyn><B>ikleyn(52781)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ikleyn><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=ikleyn><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=838567\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> .\r<BR>\n" );
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document.write( "I do not think that \"indirectly proportional\" is a correct Math term.\r<BR>\n" );
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document.write( "I do not think that \"indirectly proportional\" is a Math term, at all.\r<BR>\n" );
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document.write( "There is commonly accepted term \"inversely proportional\" in Math,<BR>\n" );
document.write( "but I NEVER saw the term \"indirectly proportional\" in peer reviewed Math textbooks.\r<BR>\n" );
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document.write( "When I come with the term \"indirectly proportional\" to Google, it shows the results<BR>\n" );
document.write( "for \"inversely proportional\" only and instead.\r<BR>\n" );
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document.write( "Could you give a precise reference to your textbook (its name, author, ISBN number, year of publication, publishing company).\r<BR>\n" );
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document.write( "I doubt that it is a normal/regular printed peer reviewed Math textbook.\r<BR>\n" );
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