Hurst gets frustrated with his calculator and opens the window in the middle of class. He throws it at 25 feet/sec from 50 feet above the ground.

We determine first the real dimension of the circular fountain by using the scale factor given. 
                             (18 cm) x (4 ft / 3 cm) = 24 ft
Then, calculate for the area of the base of the circular fountain by the equation,
                                A = πD²/4
where A is are and D is diameter. Substituting,
                               A = π(24 ft)²/4 = 144π ft² ≈ 452.4 ft²

Thus, the area of the base of the circular fountain is approximately 452.4 ft².