Answer:
84
Step-by-step explanation:
The sum of the differences of the current scores from average is ...
(84 -85) +(92 -85) +(71-85) +(94 -85) = -1 +7 -14 +9 = 1
So, to make the total of all differences from average be zero, Steve must get a score of 85 -1 = 84 on his 5th test.