Here's a simple challenge. Write a function to get the Nth percentile for a given list of numbers.
So for the 80 percentile of
(1 2 3 4 5 6 7 8 9) would be like.
(nth 80 '(1 2 3 4 5 6 7 8 9))
would be 8,
and the 75 percentile of
(nth 75 '(2 5 6 3 1 9 7 10 14 3 12 8 4 11 13 5))
??