wendy_avl said:

One practical note: write down what you did and when, before you need it.

Agreed, with the usual condition: that holds for the average and this board is a collection of individuals. A population claim and a personal prediction are different things and get quoted interchangeably.

I would rather be corrected than agreed with, if it comes to it.

wendy_avl said:

One practical note: write down what you did and when, before you need it.

Saving this. It is the first explanation that did not require me to already understand it.

Clinical perspective, offered as context rather than as advice. Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the correction. That is slower than asserting, and it is the only version that survives being wrong.

traveltech_sara said:

Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the…

This is my experience too, for whatever a second data point is worth.

Reporting back.

Late follow-up. I did not do what was suggested, I did something adjacent, and it worked; posting the difference in case it matters to somebody.