# 7 billion

Looks like by all accounts, there are now 7 billion people in the world today. At least that’s what wikipedia says. Here are two blog posts on the subject from the math blogging community. I have to say, I was surprised to see that wolframalpha doesn’t know anything about this important event (I’m sure it won’t be the last time alpha disappoints me). Anyway, I hope everyone feels humbled to be just one of the crowd.

And, happy birthday to Karl Weierstrass!

# Population Mean & Median

Have you seen this map, which shows the geographic center of the USA and also plots the current median and mean of the population? Very interesting! I got it from another math teacher, but I think the original source is the US Census Bureau (that’s what the bottom of the file says at least!). It inspired me to do some more poking around, and in the wikipedia article I found this map of how the population mean has moved over the last two centuries. Cool.

The movement of the population mean 1790-2010

And of course, here’s the median’s movement over time, too:

Movement of the Population Median

# 200 Countries over 200 Years: Visual Data Analysis

Dr. Gene Chase guest author again.

The video at Joy of Stats shows 200 countries’ health and wealth over 200 years. The augmented reality (AR) presentation makes it interesting even if you’re not a geek like me.

My favorite part of Statistics isn’t numerical. It’s graphical. Visual data analysis is powerful because our eyes coupled with our minds are able to see patterns that no amount of means, modes, medians, and standard deviations can show.

# The Extended Bell Curve

Today’s GraphJam. This goes out to my Precalculus class from last year–especially one of you. You know who you are!

One might say that this dinosaur is a ‘head above the rest’… (groan :-)).