To find the cube root of 81, we are looking for a number \( x \) such that \( x^3 = 81 \).
Calculating the cube root: \[ \sqrt[3]{81} \approx 4.326 \]
Since this is not a whole number, we can say:
- \(-9\) is incorrect since \((-9)^3\) is \(-729\).
- \(27\) is incorrect since \(27^3\) is \(19683\).
- \(9\) is incorrect since \(9^3\) is \(729\).
- \(81^{\frac{1}{3}} \approx 4.326\)
Thus, none of the provided responses are correct. The cube root of \(81\) is approximately \(4.326\).