15-22: Related Quantities. Write a short statement that expressesa possible relationship between the variables. Example: (age, shoe size) Solution: As a child ages, shoe size increases. Once the child is full- grown, shoe size remains constant. 15. (volume of gas tank, cost to fill the tank) 16. (time, price of a Ford sedan), where time represents years from 1975 to 2017 17. (latitude, ocean temperature on a given day) 18. (area of a parking lot, number of cars that can be parked in the lot) 19. (travel time from Denver to Chicago, average speed of a car) 20. (rate of pedaling, speed of bicycle) 21. (gas mileage of car, cost of driving 500 miles) 22. (annual percentage rate (APR), balance in savings account after 10 years)