Given that "A statue of Thomas Jefferson was made using a scale of 3 feet = 1 foot"
which means statue is 3 times of the actual height.
So if the actual height is x feet then statue will be of height 3x feet.
Hence required expression is given by "3x" feet.
Now second part of question is asking to find the actual height when height of the statue is 19 feet.
So the expression 3x will be equal to 19 feet
Hence final answer is approx 6.3 feet. Or to be more accurate you can write feet.