Convert 9.01: Decimal Representation Problem

Let's convert the decimal $9.01$ into a mixed number step-by-step:

• Step 1: Identify the integer part and the decimal part of $9.01$.
  The integer part is $9$ and the decimal part is $0.01$.
• Step 2: Convert the decimal part $0.01$ to a fraction.
  $0.01$ is equivalent to $\frac{1}{100}$ because $0.01$ means 1 part of 100 (i.e., hundredths).
• Step 3: Form the mixed number using the integer part and the fractional part.
  Combine the integer part $9$ with the fractional part $\frac{1}{100}$:
  \$9 + \frac{1}{100} = 9\frac{1}{100}$.

Thus, the decimal $9.01$ is equivalent to the mixed number $9\frac{1}{100}$.

Referring to the options provided, the correct answer is choice 4: $9\frac{1}{100}$.

Therefore, the solution to the problem is $9\frac{1}{100}$.