Let's begin by listing out the information given to us:
scale model: length = 1 foot, window = 1 1/2 inch = 1.2 in
actual house: length = 50 feet, window = ?
Let's state it in direct proportion form as shown below:
1 ft = 1.2 in
50 ft = x
We cross multiply to solve for the unknown variable (x), we have:
[tex]\begin{gathered} 1ft\cdot x=1.2in\cdot50ft \\ x\cdot ft=60\cdot ft\cdot in \\ \text{divide both sides by 'ft', we have:} \\ x=60in \end{gathered}[/tex]