This Structure is Habitat in Canada. I need help labeling the structuralrm

$(7\mathrm{.}5$ pts$)$ A U$-$tube manometer is connected to a closed tank containing air and water. At the closed end

of me manometer the pressure is $1\mathrm{.}3$ psig $.$ Determine the pressure reading in the gage $($in $I\frac{b}{f}{t}^2)$ for a

manometer differential reading of $4$ ft $.$ Take $y$ of the gage fluid $=90l\frac{b}{f}{t}^3.$