Answer:
The area of the actual wall is 693 square feet.  
Step-by-step explanation:
Step 1 :
Finding the length of the wall in feet.  
Length of the wall in the scale drawing  =  28 inches
Length  of the actual  wall   =   feet
 feet
Length  of the  actual wall  =   feet
 feet
Length  of the actual  wall   =  42 feet
Step 2 :  Finding the width of the wall in feet.  
Width of the wall in the scale drawing  =  11 inches
Width of the actual  wall  =  feet
 feet
Width of the actual   wall  =  feet
 feet
Width of the actual   wall   =  16.5 feet
Step 3 :  
Find area of the wall in square feet.  
Area of the actual  wall  =  Length x Width  
Area of the actual  wall  =  42 x 16.5
Area of the  actual wall  =  693 square feet.