Answer
Yes they form a proportion.
Step-by-step explanation
Ratio is a division. For the two ratios to be proportional, then they must be the same after been simplified to their simplest form.
So in this case we have to ask ourselves whether 30/12 = 80/32.
30/12 = 2.5
30/12 = 15/6 = 5/2
80/32 = 2.5
80/32 = 40/16 = 20/8 = 10/4 = 5/2
The two ratios are the same, so we can say that the ratios are proportional.