standard deviation

[Guest]

I would very much appreciate for any help in solving this problem.

I have two sets of data, a group and a control group, where I am calculating an average for each set. How could I go about calculating the standard deviation using access?

Cheers

 

[GreySky]

Standard deviation can be calculated by the same query
that produces your average; instead of selecting "avg,"
you would use:

StDev (uses n-1) or
StDevP (uses n; "standard devation of a population")

If you're talking about the coefficient of correlation
(i.e., r) between two sets of data, then that's a
different monster entirely.

SELECT (SUM(Representative * Competitor) - SUM
(Representative)
* SUM(Competitor) / COUNT(*))
/ SQRT((SUM(Representative * Representative)
- SUM(Representative) * SUM(Representative) / COUNT
(*))
* (SUM(Competitor * Competitor) - SUM(Competitor)
* SUM(Competitor) / COUNT(*))) AS r

David Atkins, MCP