Benford’s Law

Sun, 09 Mar 2008 19:11:48 +0000

I was going through Statistics Hacks and came across Benford’s Law, which states that in naturally occurring numerical data, the distribution of the first, non-zero significant digit follows a logarithmic probability distribution described as:

P(D1 = d) = log10 (1 + 1/d)

In other words, first number is much more likely going to be a 1 than it is a 9. The pretty graph to the right shows the likely occurrence of the first digit. It’s counter-intuitive, as one would assume the digits would be uniformly distributed. However, it’s been observed in a variety of areas like multiples of numbers2, blackbody radiation, physical constants, area of rivers, population and New York Times front pages[9].

Trick question

Fri, 12 Oct 2007 05:22:00 +0000

Costco called last night to let me know the tires I ordered were in — not that I expected to wait long for a set of all-weather radials compatible a 2002 Subaru, especially in this neck of the woods. I drove today, anticipating I’d be able to escape work early and have them mounted.

On the way in, I saw a cyclist, his blinkie was barely visible. Issaquah-Pine Lake is a terrible stretch of road to drive on. Biking is even worse because of the disappearing shoulder. I made a deliberate effort to give him sufficient berth. As I eased back into the normal lane position, I saw the cars in front of me were making sudden stops. I did my Fred Flinstone, feeling the pulse of the anti-lock system working its magic. Even with well-worn tires, the car held steady, and I stopped in time.

Random on WT8P's Notes to Self

Benford’s Law

Trick question