MSV 17: Four-Point PMCC

This activity will probably make purist statisticians scream,
but if you are someone like me, you become curious about the qualities that the functions arising in statistics possess,
quite independently of considerations of what is sensible statistically.
This is another example where turning the question on its head makes it maybe more interesting.

msv-17.pdf - The Task

msv-17-ans.pdf - The Answers