On September 25.2014 Colson Corp. sold 200.000 widgetrons for 5$ per unit.
200.000*5$=1.000.000$. Same day company was paid for 40% which is 400.000$.
The rest of the money he get paid in two equal parts on November 15.2014 and January 20.2015. So Calson Corp. was paid 300.000$ on November 15.2014 and 300.000$ on January 20.2015.
The mean would be the best! The mean is when you add up all of those grades and divide by the amount of exams.
If you're solving it,
504 is the total divided by 6 tests would be 84.