Answer: The constant of proportionality is 8 for the the problem on your left! The constant of proportionality for the one on you right is 6! Hope this helps!
Step-by-step explanation: Vincent earned $24 for 3 hours and so you find out how much he gets paid for 1 hour, then you divide 24 by 3 and get 8! Later he earned $72 for 9 hours, and you do the same thing which is to divide 72 by 9 which also give you 8 and so your unit rate or constant of proportionality is 8. So for the other one Justene can bike for 12 miles in 2 hours and so you find out how many miles she can bike for 1 hours and so you divide 12 by 2 which give you 6 and she can bike 6 miles in 1 hour. Then she biked 36 miles in 6 hours and you divide 36 by 6 which give you 6 and so your constant of proportionality is 6!