No σ for you!

[KeithB]

The HP 71 reference manual seems to assume a lot:

"The sample standard deviation calculation uses n-1 as the denominator where n is the sample size. For information concerning statistical arrays, refer to the "Mathematical Discussion of HP-71 Statistical Arrays", page 334."

page 334 has no discussion of standard deviation, either population or sample.

The owner's manual is not particularly helpful, either.