A businesswoman wants to determine the difference between the costs of owning and leasing an automobile. She can lease a car for $420 per month (on an annual basis). Under this plan, the cost per mile (gas and oil) is $0. 6. If she were to purchase the car, the fixed annual expense would be $4700, and other costs would amount to $0. 08 per mile. What is the least number of miles she would have to drive per year to make leasing no more expensive than purchasing?.