Re: New Math.
One of the most useful things I learned in college was the ability to make quick approximations based on limited givens to determine if a figure is reasonable.
I'm a physicist by education and in the lower-level undergrad classes, they'd often halt the lesson at hand and ask questions like "how many snowflakes fell in MN last night", or "how many bricks are in the outer surfaces of the Empire State Building." (or more humorously, the classic questions that start with something like "consider a spherical cow, what....")
They'd then watch as the students quickly came up with basic approximations (like how many snowflakes fall per minute per a unit of area) and (bricks per unit area) and multiply things out and make sure the units clobber to the correct one. Getting under an order of magnitude was really good.
Tradesmen are often way better at this sort of thing than a bookish STEM major.
Throughout life, these types of mental exercises help immensely with quickly evaluating statements whether in current events or business issues. i.e. does the final conclusion make sense and worthy of decisions.. or is it BS.
The OP posting is good and tells lots about the state of PTC in MN. It's quite astounding and good.... just needs a little arithmetic fine-tuning.... just needs the population of MN age 21 and older and also how many let the PTC lapse and of course sig figs.... I winged it and probably am pretty close...
Edit: the renewal rate (as posted above) is actually a derivative.
and indeed does tell more of the story.
