Paul had grades of 99 and 61 on his first two tests. What minimum score must he get on his third test in order to have an average of 70?

Question

I think this is asking for the mean but I’m unsure how to do this

Answer 1

Let x = the unknown test score.  Use the formula for computing an average:

 

(99+61+x)/3 = 70

 

Solve for x.