Answer:
d. 84.5
Explanation:
You will have to put the numbers in order than cross out one from each side;
70x
80x
83
86
88x
88x
In doing this you have taken out B,E, and F. The answer would have to be somewhere in between 83 and 86, which would be around 84 and 85, so therefore the answer would be 84.5