- I really like the car we looked at. My decision will come down to the distance to cost ratio.
- The what?
- You know, how far the car can go while costing me a certain amount of money.
- Oh I get it. Come with me, I'll look it up.
- Ok I'll think about it and be back with my decision tomorrow.
- The computer says that car can is about $366 for 300 km and $510 for 1500km.
- Hmm let me think. What he gave me was two points. That means I can tell how much money it will take me to go on my trip. I estimated about 2000km for a round trip.
- If the two points he gave me were (300,366), and (1500,510), that means that my slope is 3/25 and my y-intercept is 330. Now if I make an equation it would be, Y=3/25x+330. Now if I fill in my data. That's a reasonable price.
- I did the math yesterday and found out that it would cost me about $570 for my 2000km trip. I'll take the car.
- Great! Let's go take car of some paperwork.