Yes, we should break it up
It's a multi-part challenge, which aren't allowed (the only interaction between the subchallenges is the restriction to a single language and the ability to reuse code, which is my eyes is a "small interaction", to use the terminology of the meta policy), and allowing it to remain open makes it a broken window.
I propose the following steps to rectify the situation:
- Close the challenge as off-topic, citing our policy on multi-part challenges.
- Post each of the statistics in the challenge as their own challenge (excepting those that already exist, like median):
- Arithmetic mean
- Adjacent differences (a.k.a. first-order discrete differences)
- Sorting ascending
- Standard deviation
- Optionally move duplicate challenges' targets to the appropriate subchallenge. This isn't terribly important, but it would be nice to have the dupe targets correct.