standard deviation

[Novaember]

Hello
I have a quality database and I calculated the standard deviation for my accuracy rate.

I have calculated:
the accuracy rate + 1 standard deviation (STDevplus1)
the accuracy rate + 2 standard deviations (STDevplus2)
the accuracy rate - 1 standard deviation (STDevminus1)
the accuracy rate - 2 standard deviations (STDevminus2)

Now.. I'm trying to make sure that these totals don't display weird numbers
For example if my accuracy rate is 97% and my standard deviation is 8.6% then my standard deviation +1 is 105.6%. But since my accuracy rate can never be over 100% I only want to display 100% when it goes over.

I wrote something like this: STDevplus1limited: IIf([STDevplus1]>"100",100,[STDevplus1])

but with that i get 105.6%.

If i change it to: STDevplus1limited: IIf([STDevplus1]>100,100,[STDevplus1])
I get 105.6%

If I change it to: STDevplus1limited: IIf([STDevplus1]>100,"100",[STDevplus1])
I get everything after the decimal point.

I'm stumped.
Thanks!
~Nova

 

[vbaInet]

What is the algorithm for calculating a S.D.?

 

[Novaember]

What is the algorithm for calculating a S.D.?

I'm just using the STDev function that is built into access.

the calculations are correct (I compared them to what I get in Excell) it i just the display that I need help with.

I don't want anything to display over 100%

 

[The_Doc_Man]

It's a complex formula requiring a couple of sums.

I wonder if you have a mode-mixing problem.

IIf([STDevplus1]>100.0,100.0,[STDevplus1])

 

[Novaember]

It's a complex formula requiring a couple of sums.

I wonder if you have a mode-mixing problem.

IIf([STDevplus1]>100.0,100.0,[STDevplus1])

Yes I have the Accuracy Rate calculated - that is a calculated value in a query. (queryProdAnalystAccuracyRate)

Then I have another query that takes that calculated value and finds the Standard Deviation. (queryProdAnalystSTDev)

And then another query that uses the Accuracy Rate and either + or - the standard deviation to give me the +1, +2, -1, -2 deviations. (queryProdAnalystSTDevCalculations)

Once I have all the calculated deviations I have verified that the calculations are correct.

but I just don't want the +1 and +2 to display over 100%.

So I have STDevplus1 (accuracy rate + 1 standard deviation)

Then I tried the above queries and then tried to write: STDevplus1limited: IIf([STDevplus1]>"100.0",100,[STDevplus1])

This would limit what displays to a maximum of 100% but it always just displays STDevplus1

I realize this is very complex.. I wish I could just tell my boss.. nope can't do it but that won't fly. (I tried already heheeh)

Thanks so much for the help!

 

[Novaember]

Omg look!
This is like the most ghetto way to doing it but it works so w/e

ProdPlus1: IIf([STDevplus1]-100<1,"100%",[STDevplus1])

That doesn't look like it should work but it does.. so awesome.
Thanks!!