All members of the plane frame in Figure are A36 steel and bend about their strong axis when sides way buckling occurs. All columns are W14 x 74 and all girders are W21 x 44. The exterior columns are...

All members of the plane frame in Figure are A36 steel and bend about their strong axis when sides way buckling occurs. All columns are W14 x 74 and all girders are W21 x 44. The exterior columns are rigidly connected to the girder. The interior columns are pinned at each end, but the girders are continuous (contain no hinges). Weak-axis column bracing is provided only at the column ends. Find the story buckling strength. Find the maximum percentage of the story buckling load that can be allocated to each interior column.