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Former Member
May 29, 2008 at 02:58 PM

Standard Deviation (formula)

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Post Author: cjsmile2106

CA Forum: Formula

Hello everyone I really hope you can help!!!

I am trying to determine the standard deviation of a formula I have used to calculated the difference. The problem is that I'm unable to use the built in function due to the formulas needing to calculate the times, and that I'm not to familiar with how to correctly wright a manula standard deviation formula. I could be way off in my calcualtions, but I can't for the life of me to get it to work correctly. The standard devation formula I'm referencing is from (KBase Article ID:c2007430), the formula is at the bottom. Below are the formulas I'm using to create my average and I was hoping to pretty much use the same formulas but just change the last part for my standard deviation. Also I'm using CR XI.

//@Intialformulawhileprintingrecords;numbervar sum_formulafield := 0;numbervar count_formulafield := 0;

//@EvalFromulawhileprintingrecords;numbervar sum_formulafield := {@compuform} + sum_formulafield;if {@Compuform} = 0 then 0 elsenumbervar count_formulafield := count_formulafield + 1;

//@TotalFormulawhileprintingrecords;

numbervar sum_formulafield;numbervar count_formulafield;numbervar sd;numbervar m;

if count_formulafield = 0 then 0 else

m := sum_formulafield / count_formulafield;

sd := sqr((sum_formulafieldsum_formulafield - count_formulafieldm*m) / count_formulafield)