Set up a ratio of the height and distances:
Let X equal the height of the tower.
1.92 / 0.4 = X / 87.6
Cross multiply:
(1.92 * 87.6) = 0.4x
Simplify:
168.192 = 0.4x
Divide both sides by 0.4:
x = 168.192 / 0.4
x = 420.48 meters tall.
Round answer as needed.