Differentiate. \[ f(x)=13 \ln x \] \[ f^{\prime}(x)= \]

Step 1 ：Differentiate the function \(f(x)=13 \ln x\).

Step 2 ：The derivative of a function in the form of \(f(x) = a \ln x\) where \(a\) is a constant is given by \(f'(x) = \frac{a}{x}\).

Step 3 ：In this case, \(a = 13\), so the derivative of the function \(f(x) = 13 \ln x\) should be \(f'(x) = \frac{13}{x}\).

Step 4 ：Final Answer: The derivative of the function \(f(x) = 13 \ln x\) is \(f'(x) = \boxed{\frac{13}{x}}\).