The ratios are .
(Write the proportion)
(Form cross products)
(Multiply: )
The ratios form a proportion.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=f50fae5261c943ffe38465312bc8d739.png\")
.![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=2ad4d649389d2f07eebf7e998fce225b.png\")
(Write the proportion) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0edcc388824de711a382640af2382553.png\")
(Form cross products) ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=90b82142ff7295db8f5fcb67d7db4a18.png\")
(Multiply: ![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=068f44a9ee0058c14b2865930714e235.png\")
)![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")