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August 13th, 2011, 11:49 AM  #1 
Senior Member Joined: Jul 2009 Posts: 136 Thanks: 0  mean proportions
Hello all! I can find the mean proportion of ab and bc (it was the first, and simplest, problem) as b squared = ac or b = the sq. root of ac. Whoops! I just saw that the text offers the answer as b sq. x root of ac.... i.e., b ac with the square root bracket, no = sign. And the next problem is find the mean proportion of 8a squared and 2b squared (only the a and the b are "squared"). I'm hung up on whether I should put this into an equation as 8/a squared = 2/b squared which would result in (I think) 8b sq = 2 a sq Am I on the right track or way off? I think I'm off track here! If you have a clue, then it would be appreciated. Thanks! 
August 14th, 2011, 05:53 AM  #2 
Senior Member Joined: Jul 2009 Posts: 136 Thanks: 0  Re: mean proportionsI got it!
OK, I'm a little slow but I finally got it. ab to bc means ab/x = x/bc; thus, ac (b squared) = x squared, take the square root and one has x = (b)the square root of ac. And the other problem follows similarly.... 8asquared/x = x/2bsq.; thus x squared = 16 a squared b squared, take the square root and the result is x = 4ab. Voila! 

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