Answer: The ratios are proportional
Explanation:
Tony tacos is selling 15 sodas for 10 dollars.
Nicks nachos is selling 30 sodas for 20dollars. The ratio of the number sodas sold by Tony tacos to the number of sodas sold by Nicks nachos is 15/30 = 1/2
The ratio of the cost of sodas sold by Tony tacos to the cost of sodas sold by Nicks nachos is 10/20 = 1/2
So the number of sodas sold is proportional to the cost.