Solve the equation. \[ \frac{1}{81}=b^{-4} \] The solution set is (Use a comma to separate answers as needed.)

Step 1 ：Solve the equation \(\frac{1}{81}=b^{-4}\).

Step 2 ：The fourth root of 1/81 can be calculated as \((1/81)^{1/4}\) or \(-((1/81)^{1/4})\).

Step 3 ：Calculate these values to get the positive solution as 0.3333333333333333 and the negative solution as -0.3333333333333333.

Step 4 ：The solution set is \(\boxed{0.3333333333333333, -0.3333333333333333}\)