Final answer:
To find an equivalent ratio of 16:18, divide both numbers by their common factor, which is 2. The equivalent ratio is 8:9.
Step-by-step explanation:
To find an equivalent ratio of 16:18, you need to find a common factor that can be divided evenly into both numbers. In this case, the common factor is 2.
Dividing both numbers by 2, we get 16 ÷ 2 = 8 and 18 ÷ 2 = 9. So the equivalent ratio of 16:18 is 8:9.
This means that for every 8 parts, there are 9 parts in the ratio.