Walensky added that if Americans took away one easy lesson from the pamphlet, she hoped it would be P(H|E) = (P(E|H) * P(H)) / P(E).
Seriously, do this.
P(You will get covid if you go to that party) = P(you go to that party if you get covid)*P(you get covid)/P(you go to that party)***
Doesn't seem all that useful in this form.
It seems like the key info is:
The chance other people going have covid**
and the chance you will get it from them.*
*The obvious thing to change, by:
having the party outside
(or not going)
**So, have people get a covid test before going seems like the obvious point, which is about 'Value of Information', not Bayes' theorem.
***Yes it sounds weird put like this. P(You go to that party | you get covid): this highlights that the statement is a tad underdefined.
I think it would be cool to see an example of such a pamphlet and if it were good to actually do this (at least get it in more places).
CDC Announces Plan To Send Every U.S. Household Pamphlet On Probabilistic Thinking