## Wednesday, December 26, 2012

### 33 * sqrt 6 (approximately 80.8332)

I couldn't figure out whether Alex had "66" or "99" tattooed on his fingers.  After wondering for a while (he works in a store I go to a lot) I finally asked.  It turns out they are air quotes.

But I still think of them as 66 or 99.  But I couldn't figure out which number to list this under, so I went with the geometric mean.

#### 4 comments:

1. Okay...I went out and did some searching for what the heck a geometric mean is, and am still confuses. :( I need some 'splaynin'. I guess I like the air quotes best. :)

1. By way of explanation let me start with the arithmetic mean, which is more commonly referred to as the average. The arithmetic mean (AKA average) of n numbers is the sum of those numbers divided by n. For example, the arithmetic mean of 45 and 55 (note that n = 2) is (45 + 55) / 2 = 50. The arithmetic mean of 1, 2 and 3 (here n = 3) is (1 + 2 + 3) / 3 = 2.

The geometric mean is similar, except that instead of adding the n numbers you multiply them. And instead of dividing by n, you take the nth root. In the case above, the geometric mean is the square root of 66 × 99.

33 × the square root of 6 is another way of expressing that. Amy pulled out the perfect square factors from the product, and was left with a 6 in the radical.

2. My "Like" was for Anonymous's explaination.