Ratios and Proportions

A proportion is a name we give to a statement that two ratios are equal. It can be written in two ways:

two equal fractions,    a = c
                                  b    d

using a colon,    a:b = c:d
                                                                           (note found from www.math.com)

To find the proportion you must cross multiply. 

Step 1  X = 1 ß multiply 1 by 15  =15
                          15   5 ß multiply 5 by X  =5x 
                         =5x = 15

Step 2  Divide everything by 5.

                      *All ways divide the numbers by the number front of the variables*
                         5x = 15
                         5      5