(20 Points) The spherical pressure vessel is constructed from two hemispheres bolted together at the equator. The outside diameter is 10 ft and is made of a material for which the allowable stress is allow = 25 ksi. The bolts used to secure the two halves have an allowable stress of 16 ksi and a diameter d = 1 inch. If the maximum internal pressure is 3200 psi, determine the minimum required wall thickness and the number of bolts required.