Final answer:
The equation that models the amount charged by a company for landscaping a yard is d = 180.22h, where d is the total cost and h is the number of hours. The constant of proportionality, k, is found by dividing the cost of a given job by the number of hours it takes. In this case, k is $180.22 per hour.
Step-by-step explanation:
In this problem, the amount that the company charges, represented by d, is proportional to the amount of time it takes to landscape a yard, represented by h. We are told that it costs $450.55 for a 2.5-hour job. To write an equation that models the amount charged, we can use the form d = kh, where k is the constant of proportionality. We can solve for k by dividing the cost of the 2.5-hour job by 2.5: k = $450.55 / 2.5 = $180.22 per hour. Therefore, the equation that models the amount charged is d = 180.22h.