Answer:
50.2in or 4.2ft
Step-by-step explanation:
This is a problem about proportions so I generally set up my problems like below. I just set some variable here to make it easier to refer back to the measurements for each. You don't have to do this, I am just showing it for clarity. I will convert everything to inches too. We need to find the real window height.
Mb = model building = 18in
Mw= model window = in
Rb = real building = 678ft = 8136in
Rw = real window = ?
=
=
=
=
=
= Rw
= Rw
Rw ≈ 50.2in ≈ 4.2ft