Displacemnt vs Highway Gasoline Mileage

As we can see from the plot below, there is a negative relatioinship between the engine displacement for a car and its corresponding highway miles per gallon. This makes sense since larger engines tend to use more gasoline than smaller engines to travel a given distance.

ggplot(mpg, aes(x = displ, y = hwy)) + geom_point() + geom_smooth()
## `geom_smooth()` using method = 'loess' and formula 'y ~ x'