Load the tree dataset. This dataset contains the girth (circumference), height and volume of black walnut trees. Please complete the following tasks: a. Make a new column in the dataframe that has the radius of the tree. The Girth column is the circumference, and remember Circumference = 2*Pi*r, Use this to calculate the radius of each tree, as a column in the dataframe. b. Visualize the Heights variable, and comment on its distribution. c. It would be nice (and safer) to use Girth to predict Height rather than climbing up the tree and measuring it directly. Make a scatterplot of this to see if this looks like a good idea (no need to do regression, just a plot). Comment on this relationship.