Guess and Check #6
In a geometry course the grade is based on six tests, each
worth 100 points. W. Orrier has an average of 88.5 on his first
four tests. What is the lowest average he could obtain on his
next two tests and still receive an overall average of 90 or better?
There are many approaches to this problem - one is to guess at what
the answer might be, and then see whether your guess will make the
final average grade bigger or smaller than 90. Then adjust your guess.
One tricky thing here is to figure out how to calculate the
overall average given the "averaged" data in the problem.
As always, be sure to explain the
work you did to arrive
at your answers!