$4,200$ uniforms per week but at a cost of $$160$ each.

a$.$ The multifactor productivity level for two shifts working $72$ hours when compared to the level of the normal two shifts.

b$.$ The labor productivity level for two shifts working $72$ hours when compared to the level of the normal two shifts.

c$.$ The weekly profits as a result of production increasing to $4,200,$ as compared to the normal production of $2,600$ uniforms