# Summarizing Associations

There is a data set built into R called `mtcars`

that includes several measures on different types of cars. Learn more about the data set using `?mtcars`

.

#### Question 1

Summarize the association between the fuel efficiency (measured in miles per gallon) and the weight of the car using a scatter plot, the correlation coefficient, and a linear model. Since we seek to explain the fuel efficiency, put that one on the y.

#### Question 2

Repeat question 1 but use the horsepower of the car instead of the weight. Compare the scatter plots: why does one of them have a higher correlation coefficient than the other?

#### Question 3

What is the better way to compare the strength of the linear relationship between these two pairs of variables (mpg and wt; mpg and hp): the correlation coefficients or the slopes of the linear models? Why?

#### Question 4

Which car has the lowest fuel efficiency given its weight?