We know that each dumpling cost $3, and

represents the number of purchased dumplings. So the total cost of some purchased dumplings will be

. Since we also know that

also represents the total cost, we can equate them to find the equation of our proportional relationship:

Now that we have our equation, to graph our line we are going to choose tow values for

, then get the values of

for each value of

, and then join the tow pair of points using a line:
- If

,

, so our first pair is (6,18)
- If

,

, so our second pair is (0,0).