Obtain the pressure in SI (Pa) necessary for shrinking the volume of water by 1% at normal temperature and pressure. Assume the compressibility of water B = 4.85 x 10^-10 1/Pa.
Consider what the β stands for. It is the constant which transforms a pressure (in Pa) into a proportional compression of volume (where 1 = initial volume). So Pβ = 0.01 (a compression of 1%). Just plug in and solve!