Explanation:
If you multiply both of the numbers or divide both of the numbers by the SAME number , the ratio is the same
Example 56:72 multiply by 2 = 112 : 144 <===this is the same ratio
56 :72 multiply by 3.5 = 196 : 252 same ratio
56:72 multiply by 1/4 = 14 : 18 same ratio
etc etc