## Challenge¶

You believe there's a linear relationship between the weight of an adult koala 🐨 and how fast it runs. You gather some data.

You fit a linear regression model to this data, `y = mx + b`

, with slope `m = -0.15`

and offset `b = 8.2`

.

- Make a scatter plot of
*speed (y) vs weight (x)*, varying the size of each point by the koala's*age*. - Overlay the linear regression line defined by
`m`

and`b`

. - Include the linear regression equation inside the Axes, near the top right. (
**Make the position of the equation independent of the data!**)

Show the plot