Ask for the funky laser machine that reads the veins. Then bewail the state of their technology when they say they don't know what you're talking about.

They finally got one, but I'll ask about that, Connie. Right now I'm working on not crying in public.

Emergency Cute stuff [link]

Thanks, WS!

I'm finally out of there. I'm treating myself to a burger an the. I have to find something to wear to my cousin's fiancée's shower this weekend. And finally a trip to Target because we're out of all the things.

OK, here is something strange. Any medical mathematicians out there? What are the odds?

Our sound program has 9 people. 2 faculty, 1 staff, and 6 students. In 3 days, we have a SECOND person in the hospital with appendix problems. First one burst over the weekend. Second one, not sure if it's burst or just enflamed (? not sure what right term is). Two out of nine in a few days? How crazy is that?

Ha, one of the faculty (who was a math major in undergrad days) asked in his Facebook, and one of his friends responded [inserted sic's as needed]

One is seven individuals will require an appendectomy during their lifetime. Average American life expectancy is 78.64 years, or about 4103 weeks. In any given week, there's a 0.021% chance that once of your students will need an appendectomy. In any given week, there's a 0.017% chance one of the remain 5 students will need an appendectomy. In any given week, there's a 0.0000036% chance 2 students will need an appendectomy. Assuming a 3 year program, with an academic year consisting of, let's say 32 weeks per year (96 total), that makes for a 0.00035% chance that 2 out of 6 MFA students would need an appendectomy in the same week, or about 1 in 300,000.

In any given week, there's a 0.0000036% chance 2 students will need an appendectomy. Assuming a 3 year program, with an academic year consisting of, let's say 32 weeks per year (96 total), that makes for a 0.00035% chance that 2 out of 6 MFA students would need an appendectomy in the same week, or about 1 in 300,000.

I don't think this is correct. Essentially you're looking for the probability that (X = 2), where X is a binomial distribution B(6, p), and p is the probability that a single given student needs an appendectomy in a single given week. (Strictly speaking, I think you want the probability that (X >= 2), but the difference is utterly negligible.)

Accepting the same starting data, we have p = 1/(7 * 4103) = 0.000035. This won't be quite right, as I strongly doubt that the risk of appendicitis is constant throughout one's life. But it's our best estimate right now. Let q = (1 - p) = almost 1. By the binomial distribution,

Pr(X = 2) = (6 2) * p^2 * q^4

That (6 2) is supposed to be combinatorial notation - that is, the number of ways you can select two students from a pool of 6. It equals 15.

Anyway, you run through that formula, and you find that the probability of two afflicted students in any one given week is about 1.82 * 10^-8, or 1 in 55 million. (I'll call it P.) Which is to say, not very likely. Assuming that there are 96 weeks where this could happen, and that each week is more or less independent of the others (not quite true, if in one week two students need an appendectomy, there are only at most four students left at risk in any future weeks; but close enough for us), then the odds that you'll be in here one week asking "What are the odds?" are:

1 - (1 - P)^96 = 1 in 573,000.

So I think the Facebook friend overstated the odds by close to double. I suspect this is because he neglected to notice that his method of picking students (first one at random, then the second one at random) double-counts every possible pair. You could wind up with, say, students B and E by picking B and then E, or by picking E and then B. The friend's methodology adds the chance of B-then-E, and then also adds the chance of E-then-B; but really, this is the same event (B-and-E together), and should only be counted once.

swoons

I started reading that and my brain fuzzed out into Peanuts Grown Up Voice "honk honk honk".

Yeah, I didn't really follow that but am very impressed!