Answer:
Jane's situation is the one which represents a porportional relationship.
Explanation:
To verify the proportionality betwen a ratio you have to divide all the ratios and all them have to get the same constant factor.
So, if you divide the matt's ratios you aren't gonna find the same constant factor
12/1=12
20/2=10
31/2=15,5
But if you try with Jane's ones:
12/1=12
24/2=12
36/3=12
This 12 is the known constant factor, which show us that these ratios are proportional.