- Using the
`mtcars`

data, create a scatterplot of the fuel efficiency as a function of weight.

- Repeat the scatterplot, but make the points
*violet* open squares of size 5.

- Repeat the scatterplot but with separate colors for cylinder levels.

- Why does the legend look like that? Fix it so there are separate colors for cylinder levels.

- Overlay separate regression lines for each cylinder level.

- Overlay a single
*firebrick* regression line over the points with a *firebrick1*-colored confidence band.

- Plot the mean and standard error of the mean of fuel efficiency for each level of cylinder and color them
*sienna*.