Two point charges are enclosed by a spherical conducting shell that has an inner and outer radius of 13.0 cm and 15.2 cm, respectively. One point charge has a charge of 1=9.30 C, while the second point charge has an unknown charge 2. The conducting shell is known to have a net electric charge of 3.30 C, but measurements find that the charge on the outer surface of the shell is 3.70 C. Determine the charge 2 of the second point charge in units of microcoulombs