# Problem

The `mtcars` data set contains measurements on a collection of cars, including
fuel efficiency, weight, and horsepower.

The variables of interest are:

* `mpg`: Miles per gallon. This is the response variable.
* `wt`: Vehicle weight, measured in units of 1000 pounds.
* `hp`: Gross horsepower.

## Question of Interest

The question is whether fuel efficiency is associated with car weight and
horsepower, and how the expected miles per gallon changes as these predictors
change.

## Notes for Interpretation

This is an observational data set. Any explanation should describe associations
in the fitted model rather than making strong causal claims.
