To illustrate, here's a sample calculation of the TOTAL PERCENT SCORE for a hypothetical student:
Exam, Query and Homework Data for Jane Doe

Exam Scores      Exam 1    83 (out of 100)
                            Exam 2    68 (out of 100)
                            Exam 3    81 (out of 100)

                            FINAL    84 (out of 100)

Query Total        15 (out of 20)

Homework Total        69 (out of 80)


 
Calculation of TOTAL PERCENT SCORE  for Jane Doe

Her Final Exam score (84) is better than her Exam 2 score (68), so we replace the 68 with 84.

So Jane has earned  83 + 84 + 81 + 84 + 15 + 69 =  416 points out of a possible 500.

           Jane Doe's TOTAL PERCENT SCORE = (416/500) X 100 = 83.2

So what is her letter grade for the course?  I will not determine how 83.2 translates into a letter grade until after the final.  So don't bother asking.  (But the information below gives some guidelines to help Jane think about letter grades.)