To answer the question above, we have to use this equation. This problem is simple,
fAV = ∫ √(3x) dx/(9 - 0) = ∫ (3x)^(1/2)
then simplify the equation
dx/9 = 31.17691497../9 ≈
Then the answer would be.
3.464
I hope I helped you with your problem. Have a nice day