Welcome to the Stats Professor Blog

When something is the result of several inputs or factors, it is rare that all the inputs matter equally. Typically, a small number of inputs matters more than all the rest combined. There is a shorthand way to refer to this phenomenon. It is called “the 80-20 principle.”

Another school was attacked by a teenager with a rifle this week. Elementary students gunned down in a place that should always feel and be safe. It is a national disgrace. Students, parents, and educators should not need to worry about this sort of tragedy. Why does this seem to affect the US more than any other country? 

It should be possible to feed two-dimensional (2D) images into a computer and use artificial intelligence to create a three-dimensional facsimile of your childhood home (or other spaces) in virtual reality.

An article from The Atlantic on life without retirement included a scary fact about retirement in America.   "... the median savings in a 401(k) plan for people between the ages of 55 and 64 is currently just $15,000, according to the National Institute on Retirement Security, a nonprofit."

I thought I would take a moment to discuss the popularity of soccer in the United States. It is hard to pin down the true popularity of a sport, but I thought two important measures could serve as a barometer of the sport's popularity in the USA: Average attendance numbers for MLS (Major League Soccer) games and MLS revenue.

A video post from the Whitehouse that asked a simple question: "If someone works full time and makes the federal minimum wage, do you know how much their annual salary is?" It is clear that the people featured in the video never learned a simple method to approximate an annual salary from an hourly wage.

In a previous post, I solved a fairly famous probability problem about two or more people having a matching birthday (in a room of size n). In this post, I will show you how to program a Texas Instruments graphing calculator to perform the calculations. The result will provide you with a handy program to impress your friends while also teaching you a little about writing programs in the TI-83 graphing calculator.

This problem is a challenge for two reasons. First, the room size is not given as a constant, which means the solution must be expressed as a formula involving n. Second, even if we assumed a fixed room size, there are a lot of possible ways to have one or more matching birthdays. For example, imagine the room has just four people in it.