$(20$ Points$)$ The spherical pressure vessel is constructed from two hemispheres

bolted together at the equator. The outside diameter is $10ft$ and is made of a

material for which the allowable stress is ${}_{\text{a}\text{l}\text{l}\text{o}\text{w}}=25$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.