Hi john, this is not the definition of what I knwo about IQ.
An IQ of 130+ is sensational, not because your intellectual age is 30% higher than your physial age.
100 is the normal IQ, however high or low that is, and the distribution of IQs is with a standard deviation of 15.
I heard about such a definition as your's, but it's outdated, see
which confirms what I rememberred about the standard deviation of IQ values.
What is true is that the norming sample has to be taken for each age group and so the IQ you get in an IQ test designed for pupils must be shifted to your age and in that regard the compuations you talked about might make sense, though it's not really making sense. The IQ doesn't grow linear with age. You learn most in your childhood and then the amount you learn lowers and with high age you rather get a backward drift, especially but not only with dementia. So the simple dividing of ages will not be the factor to take into account.
I know this other IQ definition, as I almost was a MENSA member. I proved an IQ of 133 in a comprehensive test of the Hamburg university which was taking about a whole day (8h). That was, when I was a pupil and it was to see if I qualified for intellectual giftedness. I got some sort of scholarship that would have saved me 1 or 2 semesters of studying math. I later studied physics and now am a software developer.
As you can see
here, 96% of all people fall in the IQ range of 70-130. The Mensa club has an entry IQ of 130 and so is the intellectual 2% elite.
I was on the low end of this elite and I can say it's not fun to be on this side, so I left that scholarship, I also didn't make a career as physicist, but decided for what I like best, programming.
Bye, Olaf.