a$.$ Set the objective as minimizing the value in cell E$10($Total Costs$).$

b$.$ Use the range B$4$:D$4$ as the changing variable cells.

Adjust the hours provided by each company using the following constraints:

c$.$ E$4=5500,$ the total hours of process consulting signed

d$.$ E$10$ is less than or equal to $1350000,$ the maximum third$-$party fees

e$.$ B$4$:D$4$ is less than or equal to $5000,$ the maximum hours provided by a single third$-$party provider

f$.$ B$4$:D$4$ should be an Integer

g$.$ Run Solver, keep the solution, and then return to the Solver Parameters dialog box. Save the model to the range A$14$:A$21,$ and then close the Solver Parameters dialog box.