Frequencies in Bell Curve

[Proteus]

If the frequencies within one, two and three standard deviations of the average are known (34,1%, 13,6% and 2,1%), can one calculate the frequency from a certain value?

 

More specifically, I want to know if, if it is true that Ashkanazi Jews are 10% more intelligent, how much percent is gifted. Normally, that's 2,1%. If the average IQ in Ashkenazis really is 110, then the Bell curve shifts 10 points and 13,6% should have an IQ from 125 to 135. Subtract the frequency of IQs from 125-130, add the other 2,1%, and you have the frequency of giftedness. How do I know the frequency of IQs from 125-130?

 

And please, no paranoid ragings about racialism here. I'm not Jewish myself and was merely curious about this hypothesis.

[Sisyphus]

Assuming this sub-group has a higher mean (median?) score on IQ tests, I don't see any reason to expect the score distribution would simply be a "shifted" curve congruent with the general population's curve and measured on the same scale.

[Proteus]

You mean the bell curve would not only shift but might also either become flatter or steeper? Hadn't thought of that.

[Sisyphus]

Or it might not be a traditional bell curve at all, measured on the same scale as the general pop. But we should back up - what IQ test are you talking about?