To find the mileage per gallon, you need to divide the total miles driven by the total gallons of gas used.
Mr. Gladden drove 548 miles and used 15.22 gallons of gas.
The formula for mileage per gallon (mpg) is:
\[ \text{mpg} = \frac{\text{miles}}{\text{gallons}} \]
Now plug in the numbers:
\[ \text{mpg} = \frac{548 \text{ miles}}{15.22 \text{ gallons}} \approx 36.01 \text{ mpg} \]
Therefore, the mileage per gallon for Mr. Gladden is approximately 36.01 mpg.
The correct response is 36.01 mpg.