Credit scores are on a scale from 300 - 850, with 850 being the highest credit score possible.  To give you a feel for the extremes, while the national average credit score is 678, only 13% of the nation's population has scores above 800.  At the other extreme, roughly 15% of the population has a credit score lower than 550.  In general, a good credit score is anything above 700.

So that gives you two data points to think about.  The national average credit score is 678 and a good credit score is anything above 700.  Does that mean that half of all Americans have a credit score below the national average?

The short answer is No.  In fact, 58% of Americans have credit scores above 700.  The national average is only 678 because the average is being pulled down by some very low credit scores.  Remember, we're not talking about the median score (half above and half below), we're talking about an average score.