Question

The following table represents the total cost, in dollars (y) to join a gym for x number of months. The cost includes a one-time joining fee of $10. Does the data in the table represent a proportional relationship or a non-proportional relationship? How do you know?

x 1 2 3 4 5
y 25 40 55 70 85

Answer 1

Not proportional.

Explanation:

A proportional relationship has a constant of proportional which can be formed by a ratio between any y and x values of the function. The constant will be the same every time.

The ratio y/x is 25/1, 40/2, 55/3, 70/4, and 85/5. These simplify to 25, 20, 13.33, etc. These are not the same values. This is not proportional.