Versions of the following completely-made-up story have been told elsewhere. Suppose there are exactly 9 people on a bus in Seattle, and the average of their yearly incomes is $65,000. At the next stop, the highest paid person on the bus (with an income of $120,000 per year) gets off, and Bill Gates gets on. Mr. Gates makes 7.6 billion dollars a year.

What is the new average salary of people on the bus?