Assuming that the total value is in cell A2 and percent in B2, the above formula turns into a simple =A2*B2 and returns 104.50. Remember, when you type a number followed by the percent sign (%) in Excel, the number is interpreted as a hundredth of its value. For example, 11% is actually stored as 0.11 and Excel uses this underlying value in all formulas and calculations. In other words, the formula =A2*11% is equivalent to =A2*0.11.
from my understanding, shut off pressure is the the higest pressure that can be produced by a pump and this happened at zero flow i.e. control valve closed at discharge line. so when pump running during discharge valve closed, the pressure build up in the pipe line until a maximum pressure and this maximum pressure is shut off pressure.
A pump or water tank pressure control switch is designed and adjusted to turn the pump on at a cut in pressure, usually 20 psi or 30 psi, and to turn the water pump off at a cut out pressure, usually 40 psi or 50 psi.