How do I solve for T?
PI(67.2/2)^2*T*13.6g/cm^3= 5lb*435.6g
Assuming T is the height of a trough of mercury in centimetres (double check typo indicated in bold)
π(67.2/2)^2*T*13.6g/cm^3= 5lb*453.6g
Transpose multiplication to the right hand side as division:
T=(5*453.6)/(π*(67.2/2)²*13.6) cm
I'll let you use the calculator to complete the math.