Step-by-step explanation:
It is given that, the temperature in Gotham in degrees Fahrenheit (°F) t hours after 9 AM be modeled by the function as :

We need to find the average value of F from t = 0 to t = 12 s
The average value of an integral over and interval a to b is given by :


Using online calculator, the integral is given by :


So, the average value of From t = 0 to t = 12 s is 14.54 degrees Fahrenheit. Hence, this is the required solution.