Standard Deviation not calculating correctly

[Empie]

Hi there, I am using the Expression Builder & wish to calculate the sample Standard Deviation of a sample, using the Built-In Function StDev: -

Sqr([SumOfSquaredDeviationsFromTheMean] / ([Count]-1))

However, the result is the same as for the Standard Deviation of a population StDevP: -

Sqr([SumOfSquaredDeviationsFromTheMean] / [Count])


(i.e. no -1)

StDev has worked correctly before on this data in a previous version of the file, so I am wondering why not now? Any idea?

Regards.

[Micron]

Never used this function in Access but from what little I've just read, the syntax is StDev(fieldNameHere) or StDevP(fieldNameHere).
As for why it used to work and doesn't now - possibly an Office upgrade. You would not be the first to report that code stopped working after an Access or Office upgrade. It's usually because it was not properly written. Not saying that is your situation, just that I've seen that behaviour before.

[orange]

I don't recall ever using standard deviation with Access. Here's a link that may be helpful to you.
You could try the DStDEv or DStDEvP.
Good luck. And let us (others) know what you find.

[Empie]

I tried DStDev to calculate the sample standard deviation, though no luck either. The only way I could find was to recover an earlier dBase version from the cloud & copy & past the query from that into the current dBase.

[orange]

Follow up based on curiosity.
I reviewed Standard Deviation and related terms from the video here.
Then created the following in Ms Access O365.

tblDevTest
id autonumber
amnt number/single

There are 6 records containing 2 fields in the recordset.

Record id amnt

0 1 17
1 2 15
2 3 23
3 4 7
4 5 9
5 6 13

To test the Avg, stdev and Var functions in Access.

SELECT Avg(tblDEvTest.amnt) AS AvgOfamnt
FROM tblDEvTest;

AvgOfamnt
14

SELECT StDev(tblDEvTest.amnt) AS StDevOfamnt
FROM tblDEvTest;

StDevOfamnt
5.76194411635517

SELECT Var(tblDEvTest.amnt) AS VarOfamnt
FROM tblDEvTest;

VarOfamnt
33.2

All of which agree with the video example.