Find $f^{\prime}(x), f^{\prime \prime}(x)$, and $f^{(3)}(x)$ for the following function. \[ f(x)=3 e^{x} \] \[ f^{\prime}(x)= \]

Step 1 ：Find the first derivative of the function, \(f'(x) = 3e^x\)

Step 2 ：Find the second derivative of the function, \(f''(x) = 3e^x\)

Step 3 ：Find the third derivative of the function, \(f^{(3)}(x) = 3e^x\)

Step 4 ：\(\boxed{f'(x) = f''(x) = f^{(3)}(x) = 3e^x}\)