How can you check to see if two ratios form a proportion?

Ratios can also be written as fractions. So when the ratios are in fraction form, they are proportionate if they are equivalent fractions.

for example ... lets say if ur 2 ratios are 2:4 and 8:16 ... put them in fraction form ... 2/4 and 8/16 ...

2/4 reduces to 1/2

8/16 reduces to 1/2

so these 2 ratios are proportionate because they are equivalent fractions

another example ... u have 2 ratios which are 3:5 and 6:12

3/5 and 6/12

3/5 ... does not reduce

6/12 = 1/2

these are not proportionate because they are not equivalent fractions

You can use cross products to see whether two ratios are equal and form a proportion.