The Stats Guy takes a look at averages:

In this diagram, there are a bunch of numbers and a single question mark. Behind the question, is also a number. The known numbers are the same as in our friend

`v`

above.Our task is as follows:

– Make a guess on what that mystery number could be. And,

– If we can’t get it right, then reduce, as much as possible, the error we incur on our guess.

This is a well-written explanation of an important concept. H/T R-Bloggers