Question 1116940
Let each test count as 1 and the fourth test count as 2
average=total/n
80=400/5.  The tests count as 1, so the total is 65.5+71+94=230.5
That leaves 169.5 left to make 400, 400-230.5
That is the score the final will contribute, and it counts twice, so divide by 2 to get 84.75.