In the city of Lineville, the taxi rates are based on a linear equation. The cost for a 4-mile ride is $3.10, while a 7-mile ride costs $4.15.
Find a linear equation that fits the given information.

Use your equation to find the cost of a 12-mile ride.

How far can you go if you have $8 to spend on the taxi ride?

If you plan to tip the cab driver 10% of the cost of the ride, how far can you go if you have $10 to spend? Give your answer to the nearest tenth of a mile.