Hello! So first off, let's find the unit rate by dividing the price by the amount of grapes. 6.57/3 is 2.19. Grapes cost $2.19 per pound. Constant of proportionality is set up as y = kx, where "k" is the constant of proportionality, "y" is the total value, and "x" has to do with the amount". In this case, because 2.19 fills in as "k", with 3 filling in as "x", and 6.57 as "y". The constant of proportionality is 2.19.
