In order to calculate the value of a number raised to the power of a fraction, you first find the root of the number according to the value of the denominator (bottom number of the fraction).
In the example given in the question, 9 is the number provided, and the denominator of the fraction is 2.
Therefore, you would, firstly, find the square root of 9, which is 3. ²√9 = 3
Then, you would raise the answer you get to the power of the value of the numerator (top number in a fraction). In this example, the numerator is 3, so you would raise 3 to the power of 3, which gives you 27. 3³ = 27 [final answer]