Question

Is 6cups of coffee for $8 and 9 cups of coffee for $12 proportional

Answer 1

They are proportional

Explanation:

Let's simplify the ratio of coffee to cost:

6:8 :: 3:4

9:12 :: 3:4

Both simplify to 3:4, so they are proportional

Answer 2

Yes, proportional

Explanation:

Price 'P' in dollars

No. of cups 'C'

P = kC

8 = 6k

k= 8/6

k = 4/3

12 = 9k

k = 12/9

k = 4/3

Same constant, so proportional