Answer:
The scale model giraffe is 5 inches tall. 
Explanation:
To determine the size of the giraffe sculpted by the artist, knowing that it has been built on a scale of 1 inch for every 4 feet, and knowing that the real giraffe in the zoo is 20 feet, the following calculation must be performed: 
20 feet / 4 inches = X 
5 = X 
Therefore, the size of the giraffe sculpted to scale by the artist is 5 inches.