Phil is riding his bike. He rides 54 miles in 4 hours, 67.5 miles in 5 hours, and 81 miles in 6 hours. Find the constant of proportionality and write an equation to describe the situation. Let x represent the number of hours.

Sanderson is having trouble with his assignment. his shown work is as follows: − 3 7 7 3 = − 3 7 × 7 3 = − 21 21 = −1 however, his answer does not match the answer that his teacher gives him. complete the description of sanderson's mistake. find the correct answer.