stdev.P() and stdev.S() give correct values. What is stdev(), which is neither of the prevoious ones and why is it there?
It is the native ODFF of:=STDEV, see http://docs.oasis-open.org/office/v1.2/os/OpenDocument-v1.2-os-part2.html#STDEV STDEV.P is a of:=COM.MICROSOFT.STDEV.P STDEV:S is a of:=COM.MICROSOFT.STDEV.S These are needed for interoperability with MS Office.