A used car dealer is examining how the price at which a car can be sold varies with the car's mileage. What is the independent variable in this relationship?

1 Answer
Dec 10, 2017

It would be the car's mileage.


The price depends on the mileage:

higher mileage = lower price

lower mileage = higher price

Looks like an inverse relationship.

I just made up this equation: #y = (1/2)x + 10# to get a line with negative slope:

graph{-(1/2)x +10 [-1.35, 21.15, -0.675, 10.575]}

On this graph, the x-axis is mileage and the y-axis is price in thousands of dollars.

In this made-up car world,

if the car has zero mileage, it's worth $10,000;

if the car has 10,000 miles on it, it's worth $5,000:

and if the car has 20,000 miles on it, it's value is zero.

Not realistic, but this is the idea.