Figure shows a vertically loaded bracket attached to a fixed member by three identical bolts. Although the $24-kN$ load is normally applied in the center, the bolts are to be selected on the basis that the load eccentricity shown could occur. Because of safety considerations, SAE class $9\mathrm{.}8$ steel bolts and a minimum safety factor of $6($based on proof strength$)$ are to be used. Determine an appropriate bolt size.