04-19-2020, 07:12 PM
So check it, let's work together before he comes back. He'll never know, right? Yeah, just add this to that vast list of stuff he doesn't know and stuff he doesn't know he doesn't know - he'll be none the wiser...
Here's a tip - the actual answer, without Bayes, is 0.88. The whole point of the exercise is to show that the naive answer of 0.95 is incorrect and you need to know the fraction of the population that is infected before giving an actual answer. The only case where the answer is 0.95 is when 50% of the population is infected, as PaulW and Durian Fiend pointed out (apologies if someone else pointed that out and I missed it - all the insults muddied the thread).
I'm glad that at least some tried the exercise and realized what the problem really meant. Not so many thanks to those who posted insults. Guys, you can express the answer as an equation. That's what scientists generally do.
Here's a tip - the actual answer, without Bayes, is 0.88. The whole point of the exercise is to show that the naive answer of 0.95 is incorrect and you need to know the fraction of the population that is infected before giving an actual answer. The only case where the answer is 0.95 is when 50% of the population is infected, as PaulW and Durian Fiend pointed out (apologies if someone else pointed that out and I missed it - all the insults muddied the thread).
I'm glad that at least some tried the exercise and realized what the problem really meant. Not so many thanks to those who posted insults. Guys, you can express the answer as an equation. That's what scientists generally do.