Final answer:
The surface area of the four walls in Ashley's rectangular bedroom is 368 square feet.
Step-by-step explanation:
To find the surface area of the four walls in Ashley's rectangular bedroom, we need to calculate the perimeter of the room and multiply it by the height of the walls. The perimeter of a rectangle is the sum of the lengths of all its sides. In this case, it would be 2 times the length plus 2 times the width. So, the perimeter is (2 * 12ft) + (2 * 11ft) = 24ft + 22ft = 46ft.
Now, we multiply the perimeter by the height of the walls, which is 8ft. So, the surface area of the four walls is 46ft * 8ft = 368ft².