Question 837257
Well we could assume that this student got an 86% on all the exams, even though he probably not have, we need to add 3 numbers that average 86, and this is the easiest solution. Also, because he needs a 90% or better average on 4 exams, we must account for this by multiplying 90 by 4. This yields:

86+86+86+x<=360

Now solve:


258+x<=360

x<=102

So John must somehow earn [102%] on his next exam to get an A average.