BUG: Issue #29128 Series.var not returning the correct result
- [ x ] closes #29128
- [ x ] tests added / passed
- [ x ] passes `black pandas`
- [ x ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [ x ] whatsnew entry

This PR closes https://github.com/pandas-dev/pandas/issues/29128
Hello @HubertKl! Thanks for updating this PR. We checked the lines you've touched for [PEP 8](https://www.python.org/dev/peps/pep-0008) issues, and found:





There are currently no PEP 8 issues detected in this Pull Request. Cheers! :beers: 

##### Comment last updated at 2019-11-09 00:01:11 UTC Sorry for the mess, I ran the wrong version of black. 

I updated my PR accordingly to the change requested. @HubertKl can you rebase > @HubertKl can you rebase

Done
 Thanks @HubertKl 