Answer:
Non-proportional; the rate of change is $30/month
Explanation:
After 6 months, the total cost was $200.
After 8 months, the total cost was $260.
Find the rate of change using formula

Hence,

At this rate, after 6 months Tanya paid

But after 6 months, the total cost of Tanya’s gym membership was $200.
It means the relationship passes through the point (0,20), not through the origin. Each proportional realtionship passes through the origin. Thus, this is not proportional relationship.