Write each as a reduced fraction: \[ 0.75 \% \]

Step 1 ：Convert the percentage into a decimal by dividing by 100: \(0.75\% = 0.0075\)

Step 2 ：Convert the decimal into a fraction: \(0.0075 = \frac{3}{400}\)

Step 3 ：The fraction is already in its simplest form.

Step 4 ：Final Answer: The reduced fraction of $0.75\%$ is \(\boxed{\frac{3}{400}}\)