Good job H Rattle. For many engineering estimates we use 2 sigma to represent uncertainty and probabilities. 2 sigma is equivalent to a 95% confidence level. So assuming that your distribution is Gaussian(and that you did your math correctly), there is a 95% chance that the 43-101 will have a value between 100,000 and 900,000.

But then again, there are lies and then there is statistics. Just look at gender distribution, on average we should be half female and half male, sure there are some but hopefully not yet the norm!