Finding proportion of number relationship

Question

If a whole sandwich cost 4.50 and a half sandwich cost 3.00. Are the prices for the sanwiches proportional

Answer 1

Set up a proportion, cross-multiply, and see if it works!

 

4.50/1 = 3.00/0.5

3.00 = 2.25

 

They are not equal, so they are not proportional!