The Iron-It-Out laundromat dry cleans Lila's suits.
There is a proportional relationship between the number of suits Lila dry cleans, x, and the total cost (in dollars), y.
x (suits) y (dollars)
1 $8
6 $48
7 $56
9 $72
What is the constant of proportionality? Write your answer as a whole number or decimal.