The possible range for the cost of the wallpaper C is C ≤ $120
The first thing to do here is to caculate the the area of the wall.
Since it is a rectangular wall( dimensions are not same), we use the formula for the area of a rectangle.
Mathematically, area of a rectangle is L * B, so the area of the wall will be 8 feet * 12 feet = 96 square feet
Now, we proceed to get the range of the cost of the wallpaper that will cover the wall.
Mathematically, we can get the cost of the wallpaper by multiplying the cost per square feet of the wall paper by the area of the wall.
That would be $96 * $1.25 per square foot = $120
So the possible range for the cost of the wallpaper is the range of values that minimizes the cost for the wallpaper since it is very expensive.
Let us say the cost of the wall paper is C, then the possible range for the cost of the wallpaper will be; C ≤ $120