Five Lessons: Probability and Statistics

Comment by Howard Hendrickson Ph.D (Guest)

Howard Hendrickson Ph.D (Guest) — Tue, 29 Sep 2009 18:19:26 +0000

I have actually observered, (and it fact "called" edge in a coin toss), the incident of a coin landing on it's edge. If one thinks about what the differences are between disc and cylinder, one would find that they are the same thing, the only difference being height. In layman's terms: Increase the height of a disc, and you have a cylinder. Decrease the height of a cylinder and you have a disc. It is easy to see that there is NOT a 50/50 chance of heads or tails in a coin toss. Thought for food...

Comment by Timothy Ross (Guest)

Timothy Ross (Guest) — Wed, 05 Aug 2009 19:11:48 +0000

I am loving these 5 lessons articles!

On #4... Before you get too relaxed, don't forget that most of the times that that you are being tested for a rare disease it is because you have shown symptoms. The disease may affect 1 in 10,000 but 9,000 of those wouldn't show any signs. That would make your chances (if I do my math right) 50/50 (1/1000 or 0.1% chance of false positive and 1/1000 chance of dying within the year).

Also a quick #6 (but more psychological than mathematical):
6. Fractions are scarier than percentages
A 44 year-old woman has a 1 in 35 chance of having a baby with Down Syndrome. 1 is 35!!! I know 35 people! That is scary. Oh.. wait, 1 in 35? That is less than a 3% chance. Let's get it on!

Five Lessons: Probability and Statistics

Ken — Tue, 04 Aug 2009 17:27:44 +0000

For today: Five Lessons in Probability and Statistics.. The math behind probability is fairly straightforward, but it often leads to counterintuitive results that confuse a lot of people. I've written to some degree about this topic before. I find this kind of stuff interesting; I guess I just like proving that intuition isn't a substitute for real thought.

So here we go...