2. the average cost of a compact car at a certain dealership over the last 10 years has ranged from $14,000 to $18,500. suppose you were going to plot these points on a coordinate grid.
(a) what is a good scale to use for the y-axis? explain your reasoning.
(b) what is a good interval to use for the y-axis? explain your reasoning.

The dependent variable, average cost, must be in the y-axis. The independent variable, years, must be in the x-axis.

(a) The scale for the y-axis can be by the scale of 10,500. It should start from 14,000 to 18,500. This would maximize the space of your graph.

(b) The scale for the x-axis can be by the scale of 1 year. It should start from 1 to 10. This is practical since you record the cost per year. 

The graph can be shown in the figure. This is assuming there is a linear relationship between the two variables.