12 feet below would be -12. from -12 to 0 would be 12 feet.
from 0 to 32 above would be 32 feet.
Total distance = 12 + 32 = 44 feet.
You've got 3 values there.
Get the sum of 65, 30 and 25 and divide their sum by the number of values that exist, which in this case is 3.

Answer:
40
Answer
8x^3 - 6x^4 + 12x^3