1. Where would you add an outlier in order to maximise the correlation?
Answer

As far to the ends of the line of best fit as possible

2. Where would you add an outlier in order to minimise the correlation (or make the correlation go as far as possible in the opposite direction)?
Answer

Place the outlier as far as possible to the ends of a line which would run perpendicular to the line of best fit, crossing at the mean for X and the mean for Y

3. Where would you add a point which does not change the correlation?
Answer

On the mean for X and Y
