His total score is 27 because (3 x 2) + (4 x 3) + 4 + 5 = <<3*2+4*3+4+5=27>>27
His total number of grades is 9 because 3 + 4 +1 +1 = <<3+4+1+1=9>>9
His average grade is a 3 because 27 / 9 = <<27/9=3>>3
He earns $15 because 5 x 3 = <<5*3=15>>15
#### 15