Which equation best models the fine schedule for overdue books?
y = five-halves x, where x is the cost in cents for a book that is y days overdue
y = five-halves x, where y is the cost in cents for a book that is x days overdue
y = 5 x, where x is the cost in cents for a book that is y days overdue
y = 5 x, where y is the cost in cents for a book that is x days overdue