What is the mean?

The average, or mean, or, more formally, the arithmetic mean, is one of the simplest statistics there is. You have a bunch of numbers, you add them up, divide by how many there are, and …. That’s it! How could you go wrong with the mean? Well …. It’s surprisingly easy to do so.First, a good example, to set the stage. If you weigh 5 people (Peter, John, Mary, Ed and Sally) and they weigh 180, 190, 130, 186 and 100 pounds, you can just add that up, divide by 5 and you’ve got the average weight for those 5 people. That’s the mean. Read more!