Forum Discussion
SQRT error
Hello all,
I am new to DAX and in need of some urgnt assistence.
I am calculating the margin of error for survey results, currently attempting to do this in steps but I cannot seem to get the SQRT function to work.
The formula I am trying to create in DAX is this:
1.96*sqrt( ( p*(1-p)/n ) * ( (N-n)/(N-1) ) )
p= 0.896
I have created measures for N and n
My data looks like this and I have split the calculation into steps so I can monitor progress:
I cannot get the final step to work
MOE = SQRT(FullDataset[MOE a])
Can someone help.
I do know that the I have the result of infinity for 3 records for MOE a where n = 0. But the SQRT of infinity is infinity I didnt think it would matter.
| Course Code | N | n | MOE P ( ( p*(1-p)/n ) | FPC ( (N-n)/(N-1) ) ) | MOE a (MOE P)*(FPC) ( ( p*(1-p)/n ) * ( (N-n)/(N-1) ) ) |
| MH1231 | 4151 | 941 | 0.0001 | 0.7735 | 0.00008 |
| AC3583 | 610 | 478 | 0.0002 | 0.2167 | 0.00004 |
| MH1131 | 1671 | 400 | 0.0002 | 0.7611 | 0.00018 |
| MF1525 | 1555 | 400 | 0.0002 | 0.7432 | 0.00017 |
| AC1511 | 2313 | 388 | 0.0002 | 0.8326 | 0.0002 |
| AC1501 | 1740 | 379 | 0.0002 | 0.7826 | 0.00019 |
Any help as urgently as possible would be amazing.
Thanks so much,
K
3 Replies
Dear all,
I need some help.
I am trying to calculate the margin of error for a set of surveys.
My formula is as follows:
1.96*sqrt( ( p*(1-p)/n ) * ( (N-n)/(N-1) ) )
I cannot get the SQRT function to work in dax so I have split my work up to a series of steps to aid analysis. My data now looks like this. my measures are in bold and I have included the calculation for each one.
I now cannot get the final step of the equation to work.
MOE = SQRT(FullDataset[MOE a]) but this does not work. I get an error. Can I get a square root of a measure? Or could it be due to a few infinity results in MOE a? There is also a NaN result. Woudl this make a difference?
It seemed like this was going to be so straightforward but I am very new to this and I just cannot figure this out.
Course Code N n MOE P
( ( p*(1-p)/n )
FPC
( (N-n)/(N-1) ) )
MOE a
( ( p*(1-p)/n ) * ( (N-n)/(N-1) ) )
MH1231 4151 941 0.0001 0.7735 0.00008 AC3583 610 478 0.0002 0.2167 0.00004 MH1131 1671 400 0.0002 0.7611 0.00018 MF1525 1555 400 0.0002 0.7432 0.00017 AC1511 2313 388 0.0002 0.8326 0.0002 AC1501 1740 379 0.0002 0.7826 0.00019 Any help would be appreciated