Question

A scatterplot that relates a car's age (in years) to its value (in thousands of dollars) has a line of best fit, represented by the equation y = -2.1x + 180, where x is the car's age in years. How does the car's value change for each year it gets older?

Answer 1

The slope is -2.1, so the predicted value falls by 2.1 (thousand dollars) for each additional year of age — i.e., it loses $2,100 in value per year.