Bobby's Big Problem.
Bobby is in town on a business trip and needs to travel a lot while on this trip. He decides to rent a car since it is cheaper than calling a cab. While searching online for the best deals, he comes across two dealerships who offer are both having a promotion and both promise to have the lowest prices in town.
Option A : Cars-2-Go is having a summertime sale. The price to rent a car is $44 per day instead of their original price of $54.28 per day. This plan also includes insurance for the entire rental period.
Option B : O.T.R.T.W.N.D. (On-the-run? Then why not drive) is charging only $28 per day to rent the exact same car. However, O.T.R.T.W.N.D. sells insurance separately at a fixed cost of $64 for the entire rental period.
Which is the better deal? (assuming Bobby wants to purchase insurance as well)
The independent variable = Days.
The dependent variable = Cost($).
Describing the graphs
The P.O.I. (Point Of Intersection) is (4,176) meaning that the cost of renting the car at either dealership will be $176 on the 4th day. This means that if Bobby only needed to rent the car for 4 days, it wouldn't matter from which dealership he rented the car from because it would cost the same price either way.
Option A would be the better choice if Bobby needed to rent the car for 3 or less days.
However, if he needed the car for 5 or more days, Option B would be the better option.