Code:
  if ( 95 > studentAverage > 85 ){
C++ isn't math. You do not compare if a value is in between two values this way.
Code:
if ( studentAverage > 85 && studentAverage < 95)
That is how you compare if something is in betwen two numbers.

Secondly, you didn't answer my original question: What grade does the student get if he/she gets a 70?

Regards,

Paul McKenzie