Question

Plant A is 18 inches tall after one week, 36 inches tall after two weeks, 56 inches tall after three weeks. Plant B is 18 inches tall after one week, 36 inches tall after two weeks, 54 inches tall after three weeks. Which situation represents a proportional relationship between the plants' height and number of weeks?

Answer 1

Plan B

You take the inches and divide by the weeks to see if it is proportional. 18 x 2 is 36, so both are proportional at that point.

18 x 3 is 54.

Only B is proportional at that point.